[tex]a^{2} {c}^{2} - {a}^{2} {d}^{2} - {b}^{2} {c}^{2} + {b}^{2} {d}^{2} + 4abc[/tex]
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
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
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
A pair of shoes usually sells for $70. If the shoes are 30% off, and sales tax is 5%, what is the total price of the shoes, including tax?
Answer:
The total price of the shoes including tax is 51.45
Step-by-step explanation:
You could go about this 2 ways.
One way is if the shoes originally cost $70 and they are now 30% off, it basically means that the discounted price of the shoes is 70% of the original cost, which is $49. Then to find the total price including tax, you need to find 105% of 49, because you are adding 5% to the discounted price(100). When you do the math, you should get the answer 51.45.
The other way to do it is by first finding 30% of 70, which is 21, and then subtracting that from the original price(70) to get the discounted price, $49. Then you need to find 5% of 49 and then add that to 49 to find the total cost w/ tax, which is 51.45.
If f(x) = –8 – 5x, what is f(–4)?
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
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
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
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.
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.
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.
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.
If triangles DEF and NPQ are similar, what is the length of side d? As fraction or whole number.
The length of the side d would be 77/18.
What is the ratio of two quantities?Suppose that we've got two quantities with measurements as 'a' and 'b'
Then, their ratio(ratio of a to b) a:b
or
[tex]\dfrac{a}{b}[/tex]
If triangles DEF and NPQ are similar, then
7/9 = d/ (11/2)
By cross multiply
9d = 7 x 11/2
d = 77/2 ÷ 9
d = 77/18
Thus, The length of the side d would be 77/18.
Learn more about ratios here:
brainly.com/question/186659
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What are the next two numbers in the pattern of numbers;
45, 15, 44, 17, 40, 20, 31, 25, …
Answer:
Next two numbers are 15 and 32 respectively.
Step-by-step explanation:
The given pattern is
45, 15, 44, 17, 40, 20, 31, 25, …
Here, we have two patterns.
Odd places : 45, 44, 40, 31,...
Even places : 15, 17, 20, 25,...
In series of odd places, we need to subtract square of integers.
[tex]45-(1)^2=45-1=44[/tex]
[tex]44-(2)^2=44-4=40[/tex]
[tex]40-(3)^2=40-9=31[/tex]
So, 9th term of given pattern is
[tex]31-(4)^2=31-16=15[/tex]
In series of even places, we need to add prime numbers.
[tex]15-2=17[/tex]
[tex]17+3=20[/tex]
[tex]20+5=25[/tex]
So, 10th term of given pattern is
[tex]25+7=32[/tex]
Therefore, the next two numbers in the pattern of numbers are 15 and 32 respectively.
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
Answer:its 15.7
Step-by-step explanation:
Answer:
15.7
Step-by-step explanation:
A tree was 9 feet tall. One year later, the tree was 16 feet tall. Write an equation and use mental math to find how many feet f the tree grew.
Answer:
7 ftStep-by-step explanation:
let the height height of the tree be "h"
Hence the tree's height h=9 ft
one year later,let the height of the tree increased by x ft
hence
[tex]9 + x = 16[/tex] --------This is the equation for the growth of the tree
In order to solve for the added height(growth) of the tree we need to solve for x
[tex]9 + x = 16\\x=16-9\\x=7ft[/tex]
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?
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.
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?
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.
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
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
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
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
How many degrees was ABCD rotated?
the answer is 180°
Step-by-step explanation:
because it rotated 2x and 90+90 is 180
What is the average rate of change of f over the interval [-1, 4] Give an exact number.
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 point is a solution to y>2X-1
Answer:
Step-by-step explanation:
Answer:
B) (0,2)
Step-by-step explanation:
2 ≥ 2(0)-1
2 ≥ 0-1
2 ≥ -1
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
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
PLEASE HELP. if f(x)=x and g(x)=2, what is (f*g)(x)
Answer:
Step-by-step explanation:
hey
(f*g)(x) = f(g(x)) = f(2) = 2
second answer is correct
thanks
In a sample of real estate ads, 62% of homes for sale have garages, 19% have swimming pools, and 15% have both features. What is the probability that a home for sale has a pool, a garage or both? State your answer as a decimal, not as a percent.
Answer:
66%
Step-by-step explanation:
15% of homes have both features.
The percentage of homes that have a pool and no garage is:
Pool only = 19% - 15% = 4%
The percentage of homes that have a garage and no pool is:
Garage only = 62% - 15% = 47%
Therefore, the percentage of homes that have a pool, a garage or both is:
[tex]P = 4\%+47\%+15\%\\P=66\%[/tex]
Joshua has $4,200 to invest for college. If Joshua invests $4,200 for 3 years and earns $630, what is the simple interest rate? Joshua’s goal is to have $5,000 after 4 years. Is this possible if he invests with a rate of
return of 6%? Explain.
Answer:
The simple interest rate is 5%.
This is possible with a rate of 6%, since in this case, his amount earned will be $5,208.
Step-by-step explanation:
This is a simple interest problem.
The simple interest formula is given by:
[tex]E = P*I*t[/tex]
In which E is the amount of interest earned, P is the principal(the initial amount of money), I is the interest rate(yearly, as a decimal) and t is the time.
After t years, the total amount of money is:
[tex]T = E + P[/tex]
Joshua has $4,200 to invest for college. If Joshua invests $4,200 for 3 years and earns $630, what is the simple interest rate?
We have that [tex]P = 4200, E = 630, t = 3[/tex]. We have to find I.
[tex]E = P*I*t[/tex]
[tex]630 = 4200*I*3[/tex]
[tex]I = \frac{630}{4200*3}[/tex]
[tex]I = 0.05[/tex]
The simple interest rate is 5%.
Joshua’s goal is to have $5,000 after 4 years. Is this possible if he invests with a rate of return of 6%?
We have to find T when [tex]P = 4200, t = 4, I = 0.06[/tex]
So
[tex]E = P*I*t[/tex]
[tex]E = 4200*0.06*4[/tex]
[tex]E = 1008[/tex]
[tex]T = E + P = 4200 + 1008 = 5208[/tex]
This is possible with a rate of 6%, since in this case, his amount earned will be $5,208.
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.
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
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?
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.
f(x)= 2x^3- x^2 +x+ 1 is divided by 2x +1.
Answer:
Step-by-step explanation:
x^2
--------------------------------------------------
2x + 1 / 2x^3 - x^2 + x + 1
2x^3 + x^2
-----------------------
0 + x + 1
x + 1
The quotient is x^2 + ------------
2x + 1
4(x – 2 + y)
What the answer
Answer:
4x -8 +4y
Step-by-step explanation:
Distribute
4(x – 2 + y)
4*x -4*2 +4*y
4x -8 +4y
Any help would be appreciated
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%
For the given central angle, determine the distance traveled along the unit circle from the point (1, 0). 210 degrees a. 3.67 units c. 1.83 units b. 1.17 units clockwise d. 7.33 units
Answer:
3.67 units
Step-by-step explanation:
The central angle is at the point (0,0).
Then it's at the point (1,0)
Then it moved 210 degrees.
Let's bear in mind that we start moving the degree from it's current position.
So moving 210 degrees is moving 180 degrees plus 30 degrees.
Moving 180 degrees I like transforming linearly.
Now the location is at (-1,0)
But the distance covered will be
= 2πr*210/360
r = 1
= 2*3.142*1*(210/360)
= 6.144*0.5833333
= 3.67 units
Help me pleaseeee and thanks
Work Shown:
v - w = ( v ) - ( w )
v - w = ( -3i ) - ( 2-4i)
v - w = ( 0-3i ) - ( 2-4i)
v - w = 0-3i -2+4i
v - w = (0-2) + (-3i+4i)
v - w = -2 + i
Please answer this correctly
Answer: 363 cm squared
Step-by-step explanation:
So we can split the shape into 1 triangle and 3 rectangles.
We can start with the top right rectangle which is a 4 by 5.
4*5 = 20 cm squared
We can now do the horizontal rectangle. We need to find the dimensions firs by subtracting 4 from 31 to find the length and add 4 and 5 to find the height.
This means the dimensions are 27 by 9.
27 * 9 = 243 cm squared
Now the final square toward the bottom left will be a 10 by 7.
10 * 7 = 70 cm squared.
Now for the final piece is the triangle in the bottom left. We need to first find the height which we can determine by taking the the right hand side values of 10 , 4 and 5 and adding those together then subtracting that number by 13 to get the missing length that will add to 6 to find the height.
10 + 4 + 5 = 19
19 - 13 = 6
6 + 6 = 12
Now that we have the height and base of the triangle we solve for the area.
0.5 * 5 * 12 = 30 cm squared
Now we add all the areas together to find the total area.
20 + 243 + 70 + 30 = 363 cm squared