How would you use a completely randomized experiment in each of the following settings?
Is a placebo being used or not? Be specific and give details.

a. A charitable nonprofit organization wants to test two methods of fund-raising. From a list of 1000 past donors, half will be sent literature about the successful activities of the charity and asked to make another donation. The other 500 donors will be contacted by phone and asked to make another donation. The percentage of people from each group who make a new donation will be compared.

b. A tooth-whitening gel is to be tested for effectiveness. A group of 85 adults have volunteered to participate in the study. Of these. 43 are to be given a gel that contains the tooth-whitening chemicals. The remaining 42 are to be given a similar-looking package of gel that does not contain the tooth-whitening chemicals. A standard method will be used to evaluate the whiteness of teeth for all participants. Then the results for the two groups will be compared. How could this experiment he designed to be double-blind?

c. Consider the experiment described in part (a). Describe how you would use a randomized block experiment with blocks based on age. Use three blocks: donors younger than 30 years old. donors 30 to 59 years old. donors 60 and older.

Answers

Answer 1

Answer:

Step-by-step explanation:

a. Two methods of fund raising is being tested here in the first case study. To make a completely randomized experiment. I would use and randomly assign half the population of the 1000 donor sample that will be sent literature about the successful activities of the charity and asked to make another donation to one of the two treatment conditions: which is a sent literature about the successful activities of the charity. While the placebo group would be the other 500 donors contacted by phone and asked to make another donation with no influence whatever from the charity.

b. For the second case study, To make a completely randomized experiment. I would use and randomly assign 43 particupants which are to be given a gel that contains the tooth-whitening chemicals to the treatment condition containing the tooth-whitening chemicals while the placebo group would be the remaining 42 which are to be given a similar-looking package of gel that does not contain the tooth-whitening chemicals.

c. Using three blocks: the completely randomized design experiment would be:

Donors younger than 30 years old:

Sent literature: Yes No

Contact by phone: Yes No

Donors 30 to 59 years old:

Sent literature: Yes No

Contact by phone: Yes No

Donors 60 and older:

Sent literature: Yes No

Contact by phone: Yes No

(Yes means yes to another donation and No means no to another donation)

Answer 2

Answer:

Step-by-step explanation:

a. Two methods of fund raising is being tested here in the first case study. To make a completely randomized experiment. I would use and randomly assign half the population of the 1000 donor sample that will be sent literature about the successful activities of the charity and asked to make another donation to one of the two treatment conditions: which is a sent literature about the successful activities of the charity. While the placebo group would be the other 500 donors contacted by phone and asked to make another donation with no influence whatever from the charity.

b. For the second case study, To make a completely randomized experiment. I would use and randomly assign 43 particupants which are to be given a gel that contains the tooth-whitening chemicals to the treatment condition containing the tooth-whitening chemicals while the placebo group would be the remaining 42 which are to be given a similar-looking package of gel that does not contain the tooth-whitening chemicals.

c. Using three blocks: the completely randomized design experiment would be:

Donors younger than 30 years old:

Sent literature: Yes No

Contact by phone: Yes No

Donors 30 to 59 years old:

Sent literature: Yes No

Contact by phone: Yes No

Donors 60 and older:

Sent literature: Yes No

Contact by phone: Yes No

(Yes means yes to another donation and No means no to another donation)


Related Questions

A completely randomized design Group of answer choices has one factor and one block. has one factor and one block and multiple values. can have more than one factor, each with several treatment groups. has only one factor with several treatment groups.

Answers

Answer:

C. can have more than one factor, each with several treatment groups.

Step-by-step explanation:

A completely randomized design can be used in experimental research of a primary factor or multiple factors. The factors could have several treatment groups which are assigned in a random manner. For example, a researcher, could want to determine the effect of a drug against a disease on a class of people. To do this, he designs a treatment group with different concentrations of the drug and a placebo group. He then gets an equal number of subjects, randomly assigning them to each of the groups. The effect of both treatments are compared to know if the drug is indeed effective against the disease the researcher is experimenting on.

Completely randomized design has found application in agricultural and environmental researches.

Any help would be appreciated

Answers

Answer:

increase 40

% increase is 40 %

Step-by-step explanation:

Take the new amount and subtract the original amount

140-100 = 40

Divide by the original amount

40/100

.40

Multiply by 100 %

40%

The percent increase is 40%

The answer is 40%

1. Divide 40/100 and you will get 0.40
2. multiply 0.40 times 100 because of the 100%

Therefore, ur answer is 40%

Someone claims that the average amount of time that a freshman at TAMU studies is 7 hours. We think it’s higher than that and decide to test, using a random sample of 49 freshmen. The sample mean is 8.5 hours with a sample variance of 4 hours. What are the test statistic and p-value in this case?

Answers

Answer:

Test statistic t = 5.25

P-value = 0.000002 (one-tailed test)

Step-by-step explanation:

This is a hypothesis test for the population mean.

The claim is that the average amount of time that a freshman at TAMU studies is significantly higher than 7 hours.

Then, the null and alternative hypothesis are:

[tex]H_0: \mu=7\\\\H_a:\mu> 7[/tex]

The significance level is 0.05.

The sample has a size n=49.

The sample mean is M=8.5.

As the standard deviation of the population is not known, we estimate it with the sample standard deviation, that has a value of s=√s^2=√4=2.

The estimated standard error of the mean is computed using the formula:

[tex]s_M=\dfrac{s}{\sqrt{n}}=\dfrac{2}{\sqrt{49}}=0.29[/tex]

Then, we can calculate the t-statistic as:

[tex]t=\dfrac{M-\mu}{s/\sqrt{n}}=\dfrac{8.5-7}{0.29}=\dfrac{1.5}{0.29}=5.25[/tex]

The degrees of freedom for this sample size are:

[tex]df=n-1=49-1=48[/tex]

This test is a right-tailed test, with 48 degrees of freedom and t=5.25, so the P-value for this test is calculated as (using a t-table):

[tex]\text{P-value}=P(t>5.25)=0.000002[/tex]

As the P-value (0.000002) is smaller than the significance level (0.05), the effect is significant.

The null hypothesis is rejected.

There is enough evidence to support the claim that the average amount of time that a freshman at TAMU studies is significantly higher than 7 hours.

What’s the correct answer for this question?

Answers

Answer:

C.

Step-by-step explanation:

Central angle = 360-52=308°

In radians

308° = 308π/180

Now

S = r∅

S = 3×308π/180

S = 924π /180

S = 77π/15 in.

Answer:

answer is 13π/15

Step-by-step explanation:

correct answer is 13π/15.

An​ on-line retailer identified the web browser being used by a sample of 50 shoppers to its online site. The accompanying data table identifies the browser being used by a shopper. Previously in​ 2010, 64​% of shoppers used Browser​ A, 24​% Browser​ B, 6​% Browser​ C, 3​% Browser​ D, and 3​% Browser E.

Required:
a. Using software, tabulate the frequency of the choice of browser used by these shoppers.
b. Present a bar chart and a pie chart of these frequencies. Which is more useful to compare the distribution of these to those observed in 2010?
c. Do you see any changes in the distribution of the choice of browser?

Answers

Answer:

See Explanation

This question is answered using Microsoft Office Excel 2013

Step-by-step explanation:

Given

Browser A - 64%

Browser B - 24%

Browser C - 6%

Browser D - 3%

Browser E - 3%

Total Frequency = 50

a.

To tabulate the frequency of the choice of browser, the total frequency is multiplied by each individual percentage as follows;

Browser A - 64% * 50 = 32

Browser B - 24% * 50 = 12

Browser C - 6% * 50 = 3

Browser D - 3%* 50 = 1.5

Browser E - 3% * 50 = 1.5

See Attachment for frequency table (using software)

b. See Attachment for pie chart and bar chart.

Both charts are useful for data presentation but in this case, the pie chart is a better option to use because it shows how the distribution of each browser and how they make up as a whole.

The main circle of the pie chart shows how individual browser are distributed through segments; This is not so for the bars of the bar chart which.

c. Yes, there are changes in the choice of browser.

Aside from Browser D and E that has the same frequency, other browsers (A-C) have different frequency.

Also, the distribution shows that more users make use of browser A than other browsers and the least frequent used browser are browser D and E.

divide 41000 into two parts such that their amounts at 50% compound interest compounded annually in 2 and 3 years are equal​

Answers

Answer:24600 , 16400

Step-by-step explanation:

Let the first part be x

So, second part will be 41000 - x

For amount x

SI = prt / 100

SI = x * 0.50 * 2

SI = 1x

For amount 41000 - x

SI = (41000-x) * 0.50 * 3

SI = 61500 - 1.5x

1x = 61500 - 1.5x

1.5x + x = 61500

2.5x = 61500

x = 61500 / 2.50 = 24600 for 2 years

2nd part = 41000 - 24600 = 16400 for three years

How many degrees was ABCD rotated?

Answers

I believe it is 180º

the answer is 180°

Step-by-step explanation:

because it rotated 2x and 90+90 is 180

Find the equation of the line through the points (-3,-3) and (2,-1) using point-slope form. Then rewrite the
equation in slope-intercept form.

Answers

Answer: See below

Step-by-step explanation:

The point-slope equation is y-y₁=m(x-x₁). Since we don't know our slope, we can use the formula [tex]m=\frac{y_{2}-y_{1} }{x_{2}-x_{1} }[/tex] to find the slope. All we have to do is use the coordinate we were given and plug it into the formula.

[tex]m=\frac{-1-(-3)}{2-(-3)} =\frac{2}{5}[/tex]

Now that we have the slope, we can fill out the point-slope equation.

y-(-3)=2/5(x-(-3))

y+6=2/5(x+3)

This is the point-slope form.

Now, we can distribute and solve to get slope-intercept form.

y+6=2/5x+6/5

y=2/5x-24/5

30 points. WILL MARK BRAINLIEST

Which would be a correct first step to solve the following system of equations using the elimination method?

x + 3y = 16
2x + y = -18

A: Add the two equations together

B: Subtract the first equation from the second equation

C: Multiply the first equation by -2

D: Multiply the second equation by 2

Answers

Answer:

C: Multiply the first equation by -2

Step-by-step explanation:

-2 * (x + 3y = 16) = -2x-6y=-32

The resulting equation would be -2x-6y=-32

In the next if you add the two equations, you will successfuly eliminate x and can now solve for y.

-2x-6y=-32

2x + y = -18

Answer:

c

Step-by-step explanation:

x+3y=16________________eqn 1

2x+y=-18_______________eqn 2

multiply first equation by - 2

-2(x+3y=16)

-2x-6y= -32______________eqn 3

using elimination method

-2x-6y= -32

+

2x+y= -18

0-5y= -50

-5y= -50

divide both sides by -5

-5y/5= -50/5

y=10

substitute y in eqn 2 to find the value of x

2x+y= -18

2x+(10)= -18

2x+10= -18

2x= -18-10

2x= -28

divide both sides by 2

2x/2= -28/2

x= -14

A teacher figures that final grades in the chemistry department are distributed as: A, 25%; B, 25%;C, 40%;D, 5%; F, 5%. At the end of a randomly selected semester, the following number of grades were recorded. Calculate the chi-square test statistic x^2 to determine if the grade distribution for the department is different than expected. Use α = 0.01.


Grade A B C D F
Number 36 42 60 14 8

a. 6.87
b. 0.6375
c. 5.25
d. 4.82

Answers

Answer:

[tex]E_{A} =0.25*160=40[/tex]  

[tex]E_{B} =0.25*160=40[/tex]

[tex]E_{C} =0.4*160=64[/tex]

[tex]E_{D} =0.05*160=8[/tex]  

[tex]E_{F} =0.05*160=8[/tex]  

And now we can calculate the statistic:  

[tex]\chi^2 = \frac{(36-40)^2}{40}+\frac{(42-40)^2}{40}+\frac{(60-64)^2}{64}+\frac{(14-8)^2}{8}+\frac{(8-8)^2}{8} =5.25[/tex]  

The answer would be:

c. 5.25

Step-by-step explanation:

The observed values are given by:

A: 36

B: 42

C: 60

D: 14

E: 8

Total =160

We need to conduct a chi square test in order to check the following hypothesis:  

H0: There is no difference in the proportions for the final grades

H1: There is a difference in the proportions for the final grades

The level of significance assumed for this case is [tex]\alpha=0.01[/tex]  

The statistic to check the hypothesis is given by:  

[tex]\chi^2 =\sum_{i=1}^n \frac{(O_i -E_i)^2}{E_i}[/tex]  

Now we just need to calculate the expected values with the following formula [tex]E_i = \% * total[/tex]  

And the calculations are given by:  

[tex]E_{A} =0.25*160=40[/tex]  

[tex]E_{B} =0.25*160=40[/tex]

[tex]E_{C} =0.4*160=64[/tex]

[tex]E_{D} =0.05*160=8[/tex]  

[tex]E_{F} =0.05*160=8[/tex]  

And now we can calculate the statistic:  

[tex]\chi^2 = \frac{(36-40)^2}{40}+\frac{(42-40)^2}{40}+\frac{(60-64)^2}{64}+\frac{(14-8)^2}{8}+\frac{(8-8)^2}{8} =5.25[/tex]  

The answer would be:

c. 5.25

Now we can calculate the degrees of freedom for the statistic given by:  

[tex]df=(categories-1)=(5-1)=4[/tex]

And we can calculate the p value given by:  

[tex]p_v = P(\chi^2_{4} >5.25)=0.263[/tex]  

The p value is higher than the significance so we have enough evidence to FAIL to reject the null hypothesis

Verona is solving the equation –3 + 4x = 9. In order to isolate the variable term using the subtraction property of equality, which number should she subtract from both sides of the equation? –4 –3 3 4

Answers

Answer:

subtract  -3

Step-by-step explanation:

–3 + 4x = 9

Add 3 to each side

This is the same as subtracting -3

-3 + 4x - (-3) = 9 - (-3)

4x = 9 +3

4x = 12

Answer:
She should subtract -3 from both sides

Explanation:
To solve this problem you need to isolate the variable. To do that, you would first subtract both sides by negative three and then divide both sides by 4.
Here is what that would look like:

-3 + 4x = 9
-3 - (-3) + 4x = 9 - (-3)
4x = 12
4x / 4 = 12 / 4
x = 3

5. A company sells small, colored binder clips in packages of 20 and offers a money-back guarantee if two or more of the clips are defective. Suppose a clip is defective with probability 0.01, independently of other clips. Let X denote the number of defective clips in a package of 20. (a) The distribution of the random variable X is (choose one) (i) binomial (ii) hypergeometric (iii) negative binomial (iv) Poisson. (b) Specify the value of the parameter(s) of the chosen distribution and find the probability that a package sold will be refunded.

Answers

Answer:

a) Binomial.

b) n=20, p=0.01, k≥2

The probability hat a package sold will be refunded is P=0.0169.

Step-by-step explanation:

a) We know that

the defective probability is constant and independent.the sample size is bigger than one subject.

The most appropiate distribution to represent this random variable is the binomial.

b) The parameters are:

Sample size (amount of clips in the package): n=20Probability of defective clips: p=0.01.number of defective clips that trigger the money-back guarantee: k≥2

The probability of the package being refunded can be calculated as:

[tex]P(x\geq2)=1-(P(x=0)+P(x=1))\\\\\\P(x=k) = \dbinom{n}{k} p^{k}q^{n-k}\\\\\\P(x=0) = \dbinom{20}{0} p^{0}q^{20}=1*1*0.8179=0.8179\\\\\\P(x=1) = \dbinom{20}{1} p^{1}q^{19}=20*0.01*0.8262=0.1652\\\\\\P(x\geq2)=1-(0.8179+0.1652)=1-0.9831=0.0169[/tex]

There are 10 balls in a bag, 4 red balls and 6 black balls. If you pick one red ball, you will take it without replacement. If you pick one black ball, you will return it into the bag. Now you pick two times and each time you can only take one ball. What is the probability that you will pick two red balls

Answers

Answer:

The probability of selecting two red balls is 0.132.

Step-by-step explanation:

In a bag there are 10 balls in a bag, 4 red balls and 6 black balls.

The conditions of selecting a ball are:

If you pick one red ball, you will take it without replacement. If you pick one black ball, you will return it into the bag.

It is also provided that only one ball can be picked at a time.

Now, it is given that two balls are picked.

The number of ways to select a red ball in the first draw is: [tex]{4\choose 1}=4\ \text{ways}[/tex]

Compute the probability of selecting a red ball in the first draw as follows:

[tex]P(\text{First ball is Red})=\frac{{4\choose 1}}{{10\choose 1}}=\frac{4}{10}=0.40[/tex]

Now as a red ball is selected it will not be replaced.

So, there are 9 balls in the bag now.

The number of ways to select a red ball in the second draw is: [tex]{3\choose 1}=3\ \text{ways}[/tex]

Compute the probability of selecting a red ball in the second draw as follows:

[tex]P(\text{Second ball is Red})=\frac{{3\choose 1}}{{9\choose 1}}=\frac{3}{9}=0.33[/tex]

Compute the probability of selecting two red balls as follows:

[tex]P(\text{Two Red balls})=P(\text{First ball is Red})\times P(\text{Second ball is Red})[/tex]

                            [tex]=0.40\times 0.33\\\\=0.132[/tex]

Thus, the probability of selecting two red balls is 0.132.

Griffin’s General Store is having a 30% off sale on fans. Robert paid $25 for a fan. What is the original price of the fan?

Answers

Answer:

The original price of the fan is $35.71

Step-by-step explanation:

Since Griffin’s General Store is having a 30% off sale on fans, it simply means that fans are paying for (100%-30%)= 70%.

Let the original price be x;

Therefore, 70% of x equal to $25;

[tex]\frac{70}{100}x=25[/tex]

70/100x = 25

0.7x = 25

[tex]x = \frac{25}{0.7}[/tex]

x = 35. 71

Hence, The original price of the fan is $35.71

Answer:

$35.71

Step-by-step explanation:

The statement indicates that Robert paid $25 for a fan and that it had a 30% discount. To be able to determine the original price, you have to divide the the price with the discount by the result of 1 minus the discount.

Original price= 25/(1-0.3)

Original price= 25/0.7

Original price= 35.71

According to this, the answer is that the original price of the fan is $35.71.

x⁴+1/x⁴=47,find the value of x³+1/x³

Answers

Answer:

The value of x^3 + 1/x^3 is 47/x + 1/x^3 - 1/x^5

Step-by-step explanation:

x^4 + 1/x^4 = 47

x^4 = 47 - 1/x^4

x^3 + 1/x^3 = 1/x(x^4 + 1/x^2)

x^4 = 47 - 1/x^4

x^3 + 1/x^3 = 1/x(47 - 1/x^4 + 1/x^2) = 47/x - 1/x^5 + 1/x^3 = 47/x + 1/x^3 - 1/x^5

In right triangle $ABC,$ $\angle C = 90^\circ.$ Median $\overline{AM}$ has a length of $19,$ and median $\overline{BN}$ has a length of $13.$ What is the length of the hypotenuse of the triangle?

Answers

Answer:

  AB = 2√106 ≈ 20.591

Step-by-step explanation:

The Pythagorean theorem says the square of the hypotenuse is equal to the sum of the squares of the legs.

For median AM, we have ...

  AM² = CM² +AC² = (BC/2)² +AC²

For median BN, we have ...

  BN² = CN² +BC² = (AC/2)² +BC²

The sum of these two equations is ...

  AM² +BN² = BC²/4 +AC² +AC²/4 +BC² = (5/4)(AC² +BC²)

  AM² +BN² = (5/4)(AB²)

The hypotenuse of triangle ABC is then ...

  AB = √(4/5(AM² +BN²))

  AB = 2√((19² +13²)/5)

  AB = 2√106 ≈ 20.591

What is the approximate length of minor arc LM? Round to
the nearest tenth of a centimeter.
12.4 centimeters
15.7 centimeters
31.4 centimeters
36.7 centimeters

Answers

Answer:its 15.7

Step-by-step explanation:

Answer:

15.7

Step-by-step explanation:

For a particular disease, the probability of having the disease in a particular population is 0.04. If someone from the population has the disease, the probability that she/he tests positive of this disease is 0.95. If this person does not have the disease, the probability that she/he tests positive is 0.01. What is the probability that a randomly selected person from the population has a positive test result

Answers

Answer:

4.76% probability that a randomly selected person from the population has a positive test result

Step-by-step explanation:

We have these following probabilities:

4% probability of having the disease.

If a person has a disease, 95% probability of a positive test.

100-4 = 96% probability a person does not have the disease.

If a person does not have the disease, 1% probability of a positive test.

What is the probability that a randomly selected person from the population has a positive test result

95% of 4% and 1% of 96%. So

p = 0.95*0.04 + 0.01*0.96 = 0.0476

4.76% probability that a randomly selected person from the population has a positive test result

Please help me with this math problem

Answers

Answer:

[tex]7x^2-2x-2[/tex]

Step-by-step explanation:

[tex]-3x^2+9+10x^2-11-2x[/tex]

Combine like terms:

[tex]10x^2-3x^2-2x+9-11[/tex]

Simplify:

[tex]7x^2-2x-2[/tex]

Hope this helps!

Answer: 7x^2 - 2x - 2

Step-by-step explanation:

in this expression, all you have to do is combine like terms. those are -3x^2 and 10x^2, 9 and -11.

-3x^2 + 9 + 10x^2 - 11 - 2x     rearrange to make easier

-3x^2 + 10x^2 - 2x + 9 - 11     combine like-terms

7x^2 - 2x - 2

Which point is a solution to y>2X-1

Answers

Answer:

Step-by-step explanation:

Answer:

B) (0,2)

Step-by-step explanation:

2 ≥ 2(0)-1

2 ≥ 0-1

2 ≥ -1

A digital camcorder repair service has set a goal not to exceed an average of 5 working days from the time the unit is brought in to the time repairs are completed. A random sample of 12 repair records showed the following repair times (in days): 5, 7, 4, 6, 7, 5, 5, 6, 4, 4, 7, 5.
H0: \mu \leq 5 days versus H1: \mu > 5 days. At \alpha = .05, choose the right option.
a) Reject H0 if tcalc < 1.7960
b) Reject H0 if tcalc >1.7960

Answers

Answer:

The degrees of freedom first given by:  

[tex]df=n-1=12-1=11[/tex]  

Then we can find the critical value taking in count the degrees of freedom and the alternative hypothesis and then we need to find a critical value who accumulates 0.05 of the area in the right tail and we got:

[tex] t_{\alpha}= 1.796[/tex]

And for this case the rejection region would be:

b) Reject H0 if tcalc >1.7960

Step-by-step explanation:

Information given

5, 7, 4, 6, 7, 5, 5, 6, 4, 4, 7, 5.

System of hypothesis

We want to test if the true mean is higher than 5, the system of hypothesis are :  

Null hypothesis:[tex]\mu \leq 5[/tex]  

Alternative hypothesis:[tex]\mu > 5[/tex]  

The statistic is given by:

[tex]t=\frac{\bar X-\mu_o}{\frac{s}{\sqrt{n}}}[/tex] (1)  

The degrees of freedom first given by:  

[tex]df=n-1=12-1=11[/tex]  

Then we can find the critical value taking in count the degrees of freedom and the alternative hypothesis and then we need to find a critical value who accumulates 0.05 of the area in the right tail and we got:

[tex] t_{\alpha}= 1.796[/tex]

And for this case the rejection region would be:

b) Reject H0 if tcalc >1.7960

Me.perez drove a total of 40 miles in 5 days she drove the same number of miles each day.how many miles did me.perez drive each day?

Answers

Answer:

She drove 8 miles each day.

Step-by-step explanation:

Given that she drove equal number of miles in 5 days. So in order to find the number of miles in each days, you have to divide it by 5,

[tex]5days = 40miles[/tex]

[tex]1day = 40 \div 5[/tex]

[tex]1day = 8miles[/tex]

What is the value of expression below? 7/2-4.5x3+8

Answers

Answer:-2

Step-by-step explanation:

Ok so I’m assuming the x stands for the multiplication sign

7/2-4.5*3+8

Use pemdas

Multiplication first

7/2-4.5*3+8

-4.5*3

7/2-13.5+8

Then addition

-13.5+8

Lastly subtraction

7/2-5

-2

What is the average rate of change of f over the interval [-1, 4] Give an exact number.

Answers

Answer:

  1.4

Step-by-step explanation:

The average rate of change is the "rise" divided by the "run".

  rise/run = (f(4) -f(-1))/(4 -(-1)) = (0 -(-7))/(4+1)

  rise/run = 7/5 = 1.4

The average rate of change on the interval [-1. 4] is 1.4.

We will see that the average rate of change in the given interval is 1.4

How to find the average rate of change?

For a given function f(x), the average rate of change on an interval [a, b] is given by:

[tex]r = \frac{f(b) - f(a)}{b - a}[/tex]

In this case the interval is [-1, 4], using the graph we can see that:

f(-1) = -7

f(4) = 0

replacing that in the formula we get:

[tex]r = \frac{0 - (-7)}{4 - (-1)} = \frac{7}{5} = 1.4[/tex]

If you want to learn more about rates of change, you can read:

https://brainly.com/question/8728504

Which answer choice contains only equations? 2 + h = 14 and k minus 25 = 2 c minus 14 and d + 134 10 = 3 + s and 22 minus y 15 + x and 55 = r minus 1

Answers

Answer:

  2 + h = 14 and k - 25 = 2

Step-by-step explanation:

An equation has an equal sign.

Apparently, your answer choices are of the form ...

  (math expression) and (math expression)

In order for this to be "only equations", each "math expression" must contain an equal sign. That is, you must have ...

  ( ... = ... ) and ( ... = ... )

Something like ...

  c -14  and  d +134

contains no equal signs, so has no equations.

It looks like your appropriate choice is ...

  2 + h = 14 and k - 25 = 2

Answer:

the answer is a

Step-by-step explanation:

i took the test

:)

note: have a wonderful day!

A stack of 4 identical books is 6.28 inches high. What is the heigh of 30 of these books?

Answers

4books=6.28inches

30books=?

(30x6.28)/4

47.1 inches

answer

47.1 inches

The number of hours per week that the television is turned on is determined for each family in a sample. The mean of the data is 38 hours and the median is 34.2 hours. Twenty-four of the families in the sample turned on the television for 23 hours or less for the week. The 14th percentile of the data is 23 hours. Step 2 of 5 : Approximately how many families are in the sample? Round your answer to the nearest integer.

Answers

Answer:

There are approximately 171 families in the sample.

Step-by-step explanation:

Percentile meaning:

When a value V is said to be in the xth percentile of a set, x% of the values in the set are lower than V and (100-x)% of the values in the set are higher than V.

Twenty-four of the families in the sample turned on the television for 23 hours or less for the week. The 14th percentile of the data is 23 hours.

This means that 24 is 14% of the total number of families.

Approximately how many families are in the sample?

Using a rule of three.

24 - 0.14

x - 1

0.14x = 24

x = 24/0.14

x = 171.4

Rounding to the nearest integer

There are approximately 171 families in the sample.

Given the function f(x) = 2|x + 6|- 4, for what values of x is f(x) = 6?
x=-1, x = 11
x=-1, x=-11
x = 14, x=-26
x = 26. x=-14

Answers

Answer:

solution is [tex]\boxed{x=-1,x=-11}[/tex]

Step-by-step explanation:

f(x)=2|x+6|-4

either x+6 is positive and then |x+6|=x+6

or it is negative and |x+6| = -(x+6)=-x-6

case 1: x>=-6

f(x)= 2x+12-4=2x+8

f(x)=6 <=> 2x+8=6 <=> 2x = 6-8=-2 <=> x = -1

case 2: x<=-6

f(x)=-2x-12-4=-2x-16

f(x)=6 <=> -2x-16=6 <=> 2x=-16-6 = -22 <=> x = -11

so to recap, the solutions are x=-1 and x=-11

The value of x from the modulus value function is x = -1 and x = -11

What is Modulus Function?

Regardless of the sign, a modulus function returns the magnitude of a number. The absolute value function is another name for it.

It always gives a non-negative value of any number or variable. Modulus function is denoted as y = |x| or f(x) = |x|, where f: R → (0,∞) and x ∈ R.

The value of the modulus function is always non-negative. If f(x) is a modulus function , then we have:

If x is positive, then f(x) = x

If x = 0, then f(x) = 0

If x < 0, then f(x) = -x

Given data ,

Let the function be represented as A

Now , the value of A is

f ( x ) = 2 | x + 6 | - 4   be equation (1)

On simplifying , we get

when the value of f ( x ) = 6

Substituting the value of f ( x ) = 6 , we get

6 = 2 | x + 6 | - 4  

Adding 4 on both sides , we get

2 | x + 6 | = 10

Divide by 2 on both sides , we get

| x + 6 | = 5

And , If x is positive, then f(x) = x

If x = 0, then f(x) = 0

If x < 0, then f(x) = -x

So , the two values of x are given by

when x + 6 = -5 and x + 6 = 5

x = -1 and x = -11

Hence , the values of x of modulus function is x = -1 and x = -11

To learn more about modulus function click :

https://brainly.com/question/13682596

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uppose the correlation between two variables, math attitude (x) and math achievement (y) was found to be .78. Based on this statistic, we know that the proportion of the variability seen in math achievement that can be predicted by math attitude is:

Answers

Answer:

The proportion of the variability seen in math achievement that can be predicted by math attitude is 0.78, the same value as the correlation coefficient.

Step-by-step explanation:

The correlation coefficient r between this two variables is found to be 0.78.

This coefficient can be calculated as:

[tex]r=\dfrac{SSY'}{SSY}[/tex]

where SSY' is the sum of the squares deviation from the mean for the predicted value and SSY is the sum of the squares deviation from the mean for the criterion variable.

Then, the value of the coefficient r is giving the proportion of the variability seen in the criterion value Y that can be explained by the predictor variable X.

Answer:

r=SSY'/SSY

Step-by-step explanation:

If f(x) = –8 – 5x, what is f(–4)?

Answers

Answer:

12

Step-by-step explanation:

f(-4) = -8-5(-4) = -8+20 = 12

Answer:

f(-4) = 12

Step-by-step explanation:

f(-4) = -8 - 5(-4)

= -8 + 20

= 12

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