Answer:
Option B is correct.
It is reasonable to believe that the mean magnesium ion concentration may be greater than 199.5 as the confidence interval obtained contains values that are greater than 199.5
Step-by-step explanation:
Complete Question
Six measurements were made of the magnesium ion concentration (in parts per million, or ppm) in a city's municipal water supply, with the following results. It is reasonable to assume that the population is approximately normal.
170 201 199 202 173 153
Based on a 95% confidence interval for the mean magnesium ion concentration, is it reasonable to believe that the mean magnesium ion concentration may be greater than 199.5? (Hint: you should first calculate the 95% confidence interval for the mean magnesium ion concentration.)
A) The likelihood cannot be determined.
B) Yes
C) No
Solution
For this question, obtaining the confidence interval will give a clear solution to the problem.
Since the Confidence Interval for the population mean is basically an interval of range of values where the true population mean can be found with a certain level of confidence, if the range obtained contains values greater than the standard we are comparing against (199.5), then the confidence interval proves that the mean magnesium ion may be greater than 199.5.
But to obtain the confidence interval, we need the mean and standard deviation for the sample.
170, 201, 199, 202, 173, 153
Mean = (sum of variables)/(total number of variables)
Sum of variables = 170+201+199+202+173+153 = 1098
Total number of variables = 6
Mean = (1098/6) = 183
Standard deviation = σ = √[Σ(x - xbar)²/N]
x = each variable
xbar = mean = 183
N = number of variables = 6
Σ(x - xbar)² = (170-183)² + (201-183)² + (199-183)² + (202-183)² + (173-183)² + (153-183)²
= 169 + 324 + 256 + 361 + 100 + 900
= 2110
σ = √(2110/6) = 18.75
Mathematically,
Confidence Interval = (Sample mean) ± (Margin of error)
Sample Mean = 183
Margin of Error is the width of the confidence interval about the mean.
It is given mathematically as,
Margin of Error = (Critical value) × (standard Error of the mean)
Critical value will be obtained using the t-distribution. This is because there is no information provided for the population mean and standard deviation.
To find the critical value from the t-tables, we first find the degree of freedom and the significance level.
Degree of freedom = df = n - 1 = 6 - 1 = 5.
Significance level for 95% confidence interval
(100% - 95%)/2 = 2.5% = 0.025
t (0.025, 5) = 2.57 (from the t-tables)
Standard error of the mean = σₓ = (σ/√n)
σ = standard deviation of the sample = 18.75
n = sample size = 6
σₓ = (18.75/√6) = 7.656
95% Confidence Interval = (Sample mean) ± [(Critical value) × (standard Error of the mean)]
CI = 183 ± (2.57 × 7.656)
CI = 183 ± 19.675
95% CI = (163.325, 202.675)
95% Confidence interval = (163.3, 202.7)
It is reasonable to believe that the mean magnesium ion concentration may be greater than 199.5 as the confidence interval obtained contains values that are greater than 199.5
Hope this Helps!!!
[tex]x = \frac{b + - \sqrt{{b}^{2} - 4ac } }{2a} [/tex]
O True
O False
If it is asking if that equation is the quadratic formula, then the answer is false. The reason why is that the first 'b' should be negative
The quadratic formula is
[tex]x = \frac{-b \pm \sqrt{b^2-4ac}}{2a}[/tex]
85% of z is 106,250. What is z?
Answer:
z=12500
Step-by-step explanation:
Of means multiply and is means equals
85% *z = 106250
Change to decimal form
.85z = 106250
Divide each side by .85
.85z/.85 = 106250 /.85
z=12500
What type of infection is controlled with antibiotics?
Answer:
Bacterial infection
Step-by-step explanation:
Antibiotics are most effective against bacterial infections.
Answer:
Bacterial infection
Antibiotics are most effective against bacterial infections
A children's roller coaster is limited to riders whose height is at least 30 inches and at most 48 inches. Write two inequalities that represent the height h of riders for the roller coaster.
Answer:
h≤48 h≥30
Step-by-step explanation:
What is the slope intercept form.
Answer:
y = 1/4x + 2
Step-by-step explanation:
Since they gave you point slope form already, all you need to do is convert that into slope-intercept form. Just distribute the parenthesis and move the 4 over. Once you do so, you should get C/3rd option as your answer.
What is the average rate of change for this function for the interval from x= 1
to x = 3?
Answer:
The average rate of change is 12x=12.0x.
Description:
Function: x= 1x = 3 convert to short form: x 1x 3
Interval: x= 1 , x 3
Steps:
Input: Find the average rate of change of f(x)=3x2 on the interval [x,3x].
We have that a=x, b=3x, f(x)=3x2
Thus, f(b)−f(a)b−a=3((3x))2−(3(x)2)3x−(x)=12x.
Answer: the average rate of change is 12x=12.0x.
Please mark brainliest
Hope this helps.
Answer:
3
Step-by-step explanation:
A P E X
Find the area of the trapezoid to the nearest tenth.
Answer:
2.2 metres squared
Step-by-step explanation:
We need to find the area of this trapezoid.
The area of a trapezoid is denoted by:
[tex]A=\frac{(b_1+b_2)h}{2}[/tex], where [tex]b_1[/tex] and [tex]b_2[/tex] are the parallel bases and h is the height
Here, we already know the lengths of the two bases; they are 0.9 metres and 2.3 metres. However, we need to find the length of the height.
Notice that one of the angles is marked 45 degrees. Let's draw a perpendicular line from top endpoint of the segment labelled 0.9 to the side labelled 2.3. We now have a 45-45-90 triangle with hypotenuse 2.0 metres. As one of such a triangle's properties, we can divide 2.0 by √2 to get the length of both legs:
2.0 ÷ √2 = √2 ≈ 1.414 ≈ 1.4
Thus, the height is h = 1.4 metres. Now plug all these values we know into the equation to find the area:
[tex]A=\frac{(b_1+b_2)h}{2}[/tex]
[tex]A=\frac{(0.9+2.3)*1.4}{2}=2.2[/tex]
The answer is thus 2.2 metres squared.
~ an aesthetics lover
Ari thinks the perfect milkshake has
3
33 ounces of caramel for every
5
55 scoops of ice cream. Freeze Zone makes batches of milkshakes with
6
66 ounces of caramel and
8
88 scoops of ice cream.
What will Ari think about Freeze Zone's milkshakes?
Answer:
too much caramel
Step-by-step explanation:
3 ounces : 5 scoops = 3·2 ounces : 5·2 scoops = 6 ounces : 10 scoops
If the Freeze Zone shakes have 6 ounces : 8 scoops, then Ari will think they need more ice cream (2 scoops per shake) or less caramel.
As is, the ratio of caramel to ice cream is too high.
The percent, X, of shrinkage on drying for a certain type of plastic clay has an average shrinkage percentage :, where parameter : is unknown. A random sample of 45 specimens from this clay showed an average shrinking percentage of 18.4 and a standard deviation of 2.2. est at 5% level of significance whether the true average shrinkage percentage : is greater than 17.5 and write your conclusion. Report the p-value.
Answer:
[tex]t=\frac{18.4-17.5}{\frac{2.2}{\sqrt{45}}}=2.744[/tex]
The degrees of freedom are given by:
[tex]df=n-1=45-1=44[/tex]
The critical value for this case is [tex]t_{\alpha}=1.68[/tex] since the calculated value is higher than the critical we have enough evidence to reject the null hypothesis and we can conclude that the true mean is significantly higher than 18.4
[tex]p_v =P(t_{(44)}>2.744)=0.0044[/tex]
We see that the p value is lower than the significance level so then we can reject the null hypothesis in favor of the alternative.
Step-by-step explanation:
Information given
[tex]\bar X=18.4[/tex] represent the sample mean
[tex]s=2.2[/tex] represent the sample standard deviation
[tex]n=45[/tex] sample size
[tex]\mu_o =17.5[/tex] represent the value to verify
[tex]\alpha=0.05[/tex] represent the significance level
t would represent the statistic
[tex]p_v[/tex] represent the p value
We want to test if the true mean is higher than 17.5, the system of hypothesis would be:
Null hypothesis:[tex]\mu \leq 17.5[/tex]
Alternative hypothesis:[tex]\mu > 17.5[/tex]
The statistic is given by:
[tex]t=\frac{\bar X-\mu_o}{\frac{s}{\sqrt{n}}}[/tex] (1)
And replacing we got:
[tex]t=\frac{18.4-17.5}{\frac{2.2}{\sqrt{45}}}=2.744[/tex]
The degrees of freedom are given by:
[tex]df=n-1=45-1=44[/tex]
The critical value for this case is [tex]t_{\alpha}=1.68[/tex] since the calculated value is higher than the critical we have enough evidence to reject the null hypothesis and we can conclude that the true mean is significantly higher than 18.4
The p value would be given by:
[tex]p_v =P(t_{(44)}>2.744)=0.0044[/tex]
We see that the p value is lower than the significance level so then we can reject the null hypothesis in favor of the alternative.
Grandmother bought enough cat food for her four cats to last for 12 days. On her way home she brought back two stray cats. If she gives each cat the same amount of food every day, how many days will the cat food last
Answer:
The number of days the cat food will last is 8 days.
Step-by-step explanation:
In this case, it it provided that Grandmother bought enough cat food for her four cats to last for 12 days.
Assume that each cat consumes x portions of food each day.
Then the four cats will consume, 4x portions of food each day.
Then in 12 days the amount of food consumed by the 4 cats will be:
Total amount of cat food = 12 × 4x
= 48x.
Now, it is provided that she on her way home she brought back two stray cats.
Then the six cats will consume, 6x portions of food each day.
Compute the number of days the cat food will last as follows:
[tex]\text{Number of days the cat food will last}=\frac{\text{Total amount of cat food}}{\text{Amount of food consumed each day}}[/tex]
[tex]=\frac{48x}{6x}\\\\=\frac{48}{6}\\\\=8[/tex]
Thus, the number of days the cat food will last is 8 days.
At the beginning of the season,jamie pays full price for a ticket to see the panthers,her favorite baseball team.
Corrected Question
At the beginning of the season, Jamie pays full price($49.64) for a ticket to see the panthers, her favorite baseball team. Ticket prices decrease $0.41 for every game the panthers lose this season. the panthers currently have 33 wins and 31 losses.
(a)Represent the total change in the cost of a ticket given their losses.
(b) What is the cost of a ticket for the next game they play?
Answer:
(a)$(49.64-0.41x)
(b)$36.93
Step-by-step explanation:
(a)Cost of a Full Ticket =$49.64
Let x be the number of losses
The ticket price reduces by $0.41 for every loss
Therefore:
Ticket Price after x losses =$(49.64-0.41x)
Therefore, total change in the cost of a ticket given their losses=$(49.64-0.41x)
(b)For this season the Panthers has suffered 31 losses.
Number of Losses, x=31
Therefore, cost of a ticket for the next game they play
= $(49.64-0.41*31)
=49.64-12.71
=$36.93
"How much room is there to spread frosting on the cookie?" Clare says, "The radius of the cookie is about 3 cm, so the space for frosting is about 6 cm." Andre says, "The diameter of the cookie is about 3 inches, so the space for frosting is about 2.25 sq. in."
A. Is this question talking about area or circumference? Pick one. Why?
B. Which person is most likely correct, Clare or Andre? Why?
Answer:
(a)Area
(b)Andre is Right
Step-by-step explanation:
(a)Frost is spread on the surface of a cookie, therefore the question is talking about the area of the circular cookie.
(b)
Andre says, "The diameter of the cookie is about 3 inches, so the space for frosting is about 2.25 sq. in
Area of a Circle[tex]=\pi r^2[/tex]
Radius =Diameter/2 =3/2=1.5 Inches
Therefore, Space for frosting on the cookie
[tex]=\pi *1.5^2\\=2.25\pi$ in^2[/tex]
Andre is right.
If we divide the numerator and denominator of (6/8) by 2, will its value be changed?
(50 points)
1.No
2.Yes
3.sometimes
4.Maybe
Answer:
Step-by-step explanation:
6/8 in simplest form is 3/4 but value is still the same so
1. no
MARY PUT IN A TOTAL OF 16-1/2 8 FEET LONG. A NEARBY POLE IS 72 HOURS BABYSITTING DURING 5 DAYS FEET HIGH. HOW LONG IS ITS OF THE PAST WEEK. WHAT WAS HER SHADOW? AVERAGE WORK DAY?
Answer: 3 hours and 18 minutes.
Step-by-step explanation:
A fuel oil company claims that one-fifth of the homes in a certain city are heated by oil. Do we have reason to believe that fewer than one-fifth are heated by oil if, in a random sample of 1000 homes in this city, 136 are heated by oil? Please show all 4 steps of the classical approach clearly using α = 0.05.
Answer:
Yes, we have reason to believe that fewer than one-fifth are heated by oil.
Step-by-step explanation:
A one-sample proportion test is to be performed to determine whether fewer than one-fifth of the homes in a certain city are heated by oil.
The hypothesis can be defined as follows:
H₀: The proportion of homes in a certain city that are heated by oil is not less than one-fifth, i.e. p ≥ 0.20.
Hₐ: The proportion of homes in a certain city that are heated by oil is less than one-fifth, i.e. p < 0.20.
The information provided is:
n = 1000
x = 136
α = 0.05
Compute the sample proportion as follows:
[tex]\hat p=\frac{x}{n}=\frac{136}{1000}=0.136[/tex]
Compute the test statistic as follows:
[tex]z=\frac{\hat p-p}{\sqrt{\frac{p(1-p)}{n}}}[/tex]
[tex]=\frac{0.136-0.20}{\sqrt{\frac{0.136(1-0.136)}{1000}}}\\\\=-5.9041\\\\\approx -5.90[/tex]
The test statistic value is, -5.90.
Decision rule:
Reject the null hypothesis if the p-value of the test is less than the significance level.
Compute the p-value as follows:
[tex]p-value=P(Z<-5.90)\\\\=1-P(Z<5.90)\\\\=1-(\approx 1)\\\\=0[/tex]
The p-value of the test is, 0.
p-value = 0 < α = 0.05
The null hypothesis will be rejected at 5% level of significance.
Conclusion:
The proportion of homes in a certain city that are heated by oil is less than one-fifth.
help ,, I need help with this one ,, i’m soo confused
As the x values go up, the y values go down which means the line is higher on the left side than it is on the right side.
The 4th graph would be the correct one
Suppose that a random sample of adult males has a sample mean heart mass of x¯=310.1 grams, with a sample standard deviation of s=6.6 grams. Since adult male heart masses are generally symmetric and bell-shaped, we can apply the Empirical Rule. Between what two masses do approximately 68% of the data occur? Round your answer to the nearest tenth.
Answer:
Between 303.5 grams and 316.7 grams
Step-by-step explanation:
The Empirical Rule states that, for a normally distributed random variable:
68% of the measures are within 1 standard deviation of the mean.
95% of the measures are within 2 standard deviation of the mean.
99.7% of the measures are within 3 standard deviations of the mean.
In this problem, we have that:
Mean = 310.1 grams
Standard deviation = 6.6 grams
Between what two masses do approximately 68% of the data occur?
By the Empirical Rule, within 1 standard deviation of the mean.
310.1 - 6.6 = 303.5 grams
310.1 + 6.6 = 316.7 grams
Between 303.5 grams and 316.7 grams
SOMEONE PLEASE HELP ME ASAP PLEASE!!!
Answer:
3.6
Step-by-step explanation:
d = sqrt(3^2+2^2) = sqrt(13) = 3.6
Solve 3(a + 3) – 6 = 21.
Answer:
a=6
Step-by-step explanation:
to find the value of a you need to simplify the equation first. so...
3(a+3)-6=21 (you remove the bracket first)
3a+9-6=21
3a+3=21 (you collect the like terms then)
3a=21-3
3a=18 (then you both divide both sides by 3 to find the value of a)
a=18/3
a=6
to check your answer substitute 3 instead of a
3(a+3)-6=21
3(6+3)-6=21
3(9)-6=21 (according to BODMAS since multiplication comes first you multiply 3 with 9 before subtracting it from 6.)
29-6=21
21=21
Answer:6
Step-by-step explanation:
3(a + 3) - 6 = 21
3(a + 3) = 21 + 6
3(a + 3) =27
a + 3. = 27 ÷ 3
a + 3. = 9
a. = 9 - 3
a. = 6
Answer pls need help
The pressure p(in lbs/in^2) that a 160 pound persons shoe exerts on the ground when walking varies inversely with the area A(in in^2) of the sole of the shoe when the shoes have a sole area of 40 in^2 The pressure is 4 lbs/in^2 find equation that relates these variables
A=
01:30:4
Five times the sum of a number and 27 is greater than or equal to six times the sum of that number and 26. What is the
solution set of this problem?
Answer:
x<_ 21
Step-by-step explanation:
5(x+27)>_ =6(x+26)
5x +135 >_ 6x +156
5x >_6x +21
-x>_21
x<_21
if r is the radius of a circle and d is its diameter which of the following is an equivalent formula for the circumference c = 2 pie r
a C = pie d2
b C = pie rd
c C = pie d
d C = 2 pie d
Answer:
C
Step-by-step explanation:
C=2pier or pied
Answer:
a. C = 2πr
c. C= πd
both are correct
Please answer this correctly
Answer:
d = 2
the diagonals are the different lengths
Step-by-step explanation:
Perform the indicated operation and write the result in the form a + bi i^100
[tex]i^{100}=i^{4\cdot25}=\left(i^4\right)^{25}[/tex]
Recall that [tex]i^4=1[/tex], since [tex]i^2=-1[/tex]. Then
[tex]i^{100}=1^{25}=1[/tex]
so that in the form [tex]a+bi[/tex], we have [tex]a=1[/tex] and [tex]b=0[/tex].
Answer:
D) 1
Step-by-step explanation:
Correct on edg
f(x)<0 over (-∞, -3) and what other interval?
O (-2.4, - 1.1)
O (-3, - 1.1)
O (-1.1, 2)
O (-1.1, 0.9)
Answer:
Option (4). (-1.1, 0.9)
Step-by-step explanation:
In a graph of any function, values of f(x) are represented by the values on the y-axis for the different input values on x-axis.
For the given graph, values of f(x) are less than zero.
That means interval in which the values of the function are negative for the different values of x.
Negative values of the given function are in the intervals (-∞, -3), (-1.1, 9).
Therefore, from the given options, Option (4) will be the answer.
Answer is (-1.1,0.9)
Step-by-step explanation:
Based on the type of equations in the system, what is the greatest possible number of solutions? StartLayout Enlarged left-brace 1st Row x squared + y squared = 9 2nd row 9 x + 2 y = 16 EndLayout
Answer:
2
Step-by-step explanation:
Given the system of equations:
[Tex]x^2+y^2=9\\9x+2y=16[/tex]
Comparing [Tex]x^2+y^2=9[/tex] with the general standard equation of a circle [Tex](x-h)^2+(y-k)^2=r^2[/tex].
The first equation is an equation of a circle centred at (0,0) with a Radius of 3.
The second equation 9x+2y=16 is a straight line equation.
A straight line can only intersect a circle at a maximum of 2 points.
Therefore the greatest possible number of solutions to the equations in the system is 2.
Answer:
2
Step-by-step explanation:
and jj is gay of outer banks
A high school student took two college entrance exams, scoring 1070 on the SAT and 25 on the ACT. Suppose that SAT scores have a mean of 950 and a standard deviation of 155 while the ACT scores have a mean of 22 and a standard deviation of 4. Assuming the performance on both tests follows a normal distribution, determine which test the student did better on.
Answer:
Due to the higher z-score, he did better on the SAT.
Step-by-step explanation:
When the distribution is normal, we use the z-score formula.
In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the zscore of a measure X is given by:
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.
Determine which test the student did better on.
He did better on whichever test he had the higher z-score.
SAT:
Scored 1070, so [tex]X = 1070[/tex]
SAT scores have a mean of 950 and a standard deviation of 155. This means that [tex]\mu = 950, \sigma = 155[/tex].
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{1070 - 950}{155}[/tex]
[tex]Z = 0.77[/tex]
ACT:
Scored 25, so [tex]X = 25[/tex]
ACT scores have a mean of 22 and a standard deviation of 4. This means that [tex]\mu = 22, \sigma = 4[/tex]
[tex]Z = \frac{X - \mu}{\sigma}[/tex]
[tex]Z = \frac{25 - 22}{4}[/tex]
[tex]Z = 0.75[/tex]
Due to the higher z-score, he did better on the SAT.
(like Ross 6.28) The time that it takes to service a car is an exponential random variable with rate 1. (a) If Lightning McQueen (L.M.) brings his car in at time 0 and Sally Carrera (S.C) brings her car in at time t, what is the probability that S.C.’s car is ready before L.M.’s car? Assume that service times are independent and service begins upon arrival of the car.
Answer: provided in the explanation section
Step-by-step explanation:
The complete question says:
The time that it takes to service a car is an exponential random variable with rate 1. (a) If Lightning McQueen (L.M.) brings his car in at time 0 and Sally Carrera (S.C) brings her car in at time t, what is the probability that S.C.'s car is ready before L.M.'s car? Assume that service times are independent and service begins upon arrival of the car Be sure to: 1) define all random variables used, 2) explain how independence of service times plays a part in your solution, 3) show all integration steps. (b) If both cars are brought in at time 0, with work starting on S.C. 's car only when L.M.'s car has been completely serviced, what is the probability that S.C.'s car is ready before time 2?
Ans to this is provided in the images uploaded as it is not possible to put the symbols here...
i hope you find this helpful.
cheers !!
Please hurry
On each bounce, a ball dropped from 100 feet rises to the height
from which it has fallen. How high does the ball rise, in feet, on the 10th bounce?
Answer:
D
Step-by-step explanation:
divide 10 times starting with 100.
The answer is 25/256 or 0.09765625
The height of the ball dropped from 100 feet on the 10th bounce is 0.09766 feet
What is an equation?An equation is an expression that shows the relationship between two or more numbers and variables.
Let y represent the height of the ball after x bounce. Given that the ball rises to the height from which it has fallen, hence:
y = 100(1/2)ˣ
After the 10th bounce:
y = 100(1/2)¹⁰ = 0.09766
The height of the ball dropped from 100 feet on the 10th bounce is 0.09766 feet.
Find out more on equation at: https://brainly.com/question/2972832
Calculo el area del búmeran tomando en cuenta que su diámetro es 20 cm
Answer:
50π cm²
Step-by-step explanation:
In this case we have that the area of the boomerang has been the area of the largest semicircle minus the area of the smaller semicircles.
We know that the radius is half the diameter:
r = d / 2 = 20/2
r = 10
Now we have to:
Alargest = π · r²
Alargest = π · (10 cm) ²
Alargest = 100π cm²
Asmaller = π · r²
Asmaller = π · (5 cm) ²
Asmaller = 25π cm²
Finally, the boomerang area has been:
Aboomerang = 100π cm² - 2 · (25π cm²)
Aboomerang = 50π cm²
