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Question 1

A lab technician is tested for her consistency by taking multiple measurements of cholesterol levels from the same blood sample. The target accuracy is a variance in measurements of 1.2 or less. If the lab technician takes 16 measurements and the variance of the measurements in the sample is 2.2, does this provide enough evidence to reject the claim that the lab technician’s accuracy is within the target accuracy?

At the  = .01 level of significance, what is your conclusion?

A.Cannot determine

B.Do not reject H0. At the  = .01 level of significance there is not sufficient evidence to suggest that this technician’s true variance is greater than the target accuracy.

C.Reject H0. At the  = .01 level of significance, there is enough evidence to support the claim that this technician’s variance is larger than the target accuracy.

D. Reject H0.  At the  = .01 level of significance, there is not enough evidence to support the claim that this technician’s true variance is larger than the target accuracy.

Question 2

In an article appearing in Today’s Health a writer states that the average number of calories in a serving of popcorn is 75. To determine if the average number of calories in a serving of popcorn is different from 75, a nutritionist selected a random sample

servings of popcorn and computed the sample mean number of calories per serving to be 78 with a sample standard deviation of 7.

State the null and alternative hypotheses.

A.H0:  75, H1: < 75

B.H0:  = 75, H1:  ≠ 75

C.H0:  75, H1: > 75

D.H0: = 75, H1: > 75

Question 3

You conduct a hypothesis test and you observe values for the sample mean and sample standard deviation when n = 25 that do not lead to the rejection of H0. You calculate a p-value of 0.0667. What will happen to the p-value if you observe the same sample mean and standard deviation for a sample size larger than 25?

A.The p – value decreases

B.The p – value increases

C.The p – value may increase or decrease

D.The p – value stays the same

Question 4

Smaller p-values indicate more evidence in support of the:

A.null hypothesis

B.quality of the researcher

C.alternative hypothesis

D.the reduction of variance

Question 5

A null hypothesis can only be rejected at the 5% significance level if and only if:

A.the null hypotheses includes sampling error

B.a 95% confidence interval includes the hypothesized value of the parameter

C.a 95% confidence interval does not include the hypothesized value of the parameter

D.the null hypothesis is biased

Question 6

The null and alternative hypotheses divide all possibilities into:

A.two sets that overlap

B.two non-overlapping sets

C.as many sets as necessary to cover all possibilities

D.two sets that may or may not overlap

Question 7

A manufacturer of flashlight batteries took a sample of 13 batteries from a day’s production and used them continuously until they failed to work. The life lengths of the batteries, in hours, until they failed were: 342, 426, 317, 545, 264, 451, 1049, 631, 512, 266, 492, 562, and 298.

At the .05 level of significance, is there evidence to suggest that the mean life length of the batteries produced by this manufacturer is more than 400 hours?

A.No, because the p-value for this test is equal to .1164

B.No, because the test value 1.257 is greater than the critical value 1.115

C.Yes, because the test value 1.257 is less than the critical value 1.782

D.Yes, because the test value 1.257 is less than the critical value 2.179

Question 8

A type I error occurs when the:

A.null hypothesis is incorrectly accepted when it is false

B.sample mean differs from the population mean

C.null hypothesis is incorrectly rejected when it is true

D.test is biased

Question 9

The “Pizza Hot” manager commits a Type I error if he/she is

A.staying with old style when new style is better

B.staying with old style when new style is no better than old style

C.switching to new style when it is better than old style

D.switching to new style when it is no better than old style

Question 10

A lab technician is tested for her consistency by taking multiple measurements of cholesterol levels from the same blood sample. The target accuracy is a variance in measurements of 1.2 or less. If the lab technician takes 16 measurements and the variance of the measurements in the sample is 2.2, does this provide enough evidence to reject the claim that the lab technician’s accuracy is within the target accuracy?

Compute the value of the appropriate test statistic.

A. = 30.58

B.t = 27.50

C.z = 1.65

D. = 27.50

Question 11

The hypothesis that an analyst is trying to prove is called the:

A.elective hypothesis

B.quality of the researcher

C.alternative hypothesis

D.level of significance

Question 12

Accepted characters: numbers, decimal point markers (period or comma), sign indicators (-), spaces (e.g., as thousands separator, 5 000), “E” or “e” (used in scientific notation). NOTE: For scientific notation, a period MUST be used as the decimal point marker.

Complex numbers should be in the form (a + bi) where “a” and “b” need to have explicitly stated values.

For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is valid whereas {9i} is not.

A statistician wishes to test the claim that the standard deviation of the weights of firemen is less than 25 pounds. To do so, she selected a random sample

firemen and found s = 23.2 pounds.

Assuming that the weights of firemen are normally distributed, if the statistician wanted to test her research hypothesis at the .05 level of significance, what is the critical value?

Place your answer, rounded to 3 decimal places, in the blank. For example, 12.345 would be a legitimate entry.

Question 13

Accepted characters: numbers, decimal point markers (period or comma), sign indicators (-), spaces (e.g., as thousands separator, 5 000), “E” or “e” (used in scientific notation). NOTE: For scientific notation, a period MUST be used as the decimal point marker.

Complex numbers should be in the form (a + bi) where “a” and “b” need to have explicitly stated values.

For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is valid whereas {9i} is not.

A medical doctor wishes to test the claim that the standard deviation of the systolic blood pressure of deep sea divers is less than 450. To do so, she selected a random sample

divers and found s = 432.

Assuming that the systolic blood pressures of deep sea divers are normally distributed, if the doctor wanted to test her research hypothesis at the .01 level of significance, what is the critical value?

Place your answer, rounded to 3 decimal places, in the blank. For example, 4.567 would be a legitimate entry.

Question 14

Accepted characters: numbers, decimal point markers (period or comma), sign indicators (-), spaces (e.g., as thousands separator, 5 000), “E” or “e” (used in scientific notation). NOTE: For scientific notation, a period MUST be used as the decimal point marker.

Complex numbers should be in the form (a + bi) where “a” and “b” need to have explicitly stated values.

For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is valid whereas {9i} is not.

The ABC battery company claims that their batteries last at least 100 hours, on average. Your experience with their batteries has been somewhat different, so you decide to conduct a test to see if the company’s claim is true. You believe that the mean life is actually less than the 100 hours the company claims. You decide to collect data on the average battery life (in hours) of a random sample of n = 20 batteries. Some of the information related to the hypothesis test is presented below.

Test of H0:   100 versus H1:   100

Sample mean 98.5

Std error of mean 0.777

Assuming the life length of batteries is normally distributed, if you wish to conduct this test using a .05 level of significance, what is the critical value that you should use?   Place your answer, rounded to 3 decimal places in the blank. For example, -1.234 would be a legitimate entry.

Question 15

Accepted characters: numbers, decimal point markers (period or comma), sign indicators (-), spaces (e.g., as thousands separator, 5 000), “E” or “e” (used in scientific notation). NOTE: For scientific notation, a period MUST be used as the decimal point marker.

Complex numbers should be in the form (a + bi) where “a” and “b” need to have explicitly stated values.

For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is valid whereas {9i} is not.

The ABC battery company claims that their batteries last at least 100 hours, on average. Your experience with their batteries has been somewhat different, so you decide to conduct a test to see if the company’s claim is true. You believe that the mean life is actually less than the 100 hours the company claims. You decide to collect data on the average battery life (in hours) of a random sample of n = 20 batteries. Some of the information related to the hypothesis test is presented below.

Test of H0: 100 versus H1: 100

Sample mean 98.5

Std error of mean 0.777

Assuming the life length of batteries is normally distributed, what is the value of the test statistic used to conduct your test of hypothesis?  Place your answer, rounded to 3 decimal places in the blank. For example, -2.345 would be a legitimate entry.

Question 16

Accepted characters: numbers, decimal point markers (period or comma), sign indicators (-), spaces (e.g., as thousands separator, 5 000), “E” or “e” (used in scientific notation). NOTE: For scientific notation, a period MUST be used as the decimal point marker.

Complex numbers should be in the form (a + bi) where “a” and “b” need to have explicitly stated values.

For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is valid whereas {9i} is not.

Suppose a firm that produces light bulbs wants to know whether it can say that its light bulbs typically last more than 1500 hours. Hoping to find support for their claim, the firm collects a random sample of n = 25 light bulbs and records the lifetime (in hours) of each bulb. The information related to the hypothesis test is presented below.

Test of H0:  1500 versus H1:  > 1500

Sample mean 1509.5

Std error of mean 4.854

Assuming the life length of this type of lightbulb is normally distributed, if you wish to conduct this test using a .05 level of significance, what is the critical value that you should use? Place your answer, rounded to 3 decimal places in the blank. For example, 1.234 would be a legitimate entry.

Question 17

Accepted characters: numbers, decimal point markers (period or comma), sign indicators (-), spaces (e.g., as thousands separator, 5 000), “E” or “e” (used in scientific notation). NOTE: For scientific notation, a period MUST be used as the decimal point marker.

Complex numbers should be in the form (a + bi) where “a” and “b” need to have explicitly stated values.

For example: {1+1i} is valid whereas {1+i} is not. {0+9i} is valid whereas {9i} is not.

A survey determines that mint chocolate chip is the favorite ice cream flavor of 6% of consumers. An ice cream shop determines that of 240 customers, 18 customers stated their preference for mint chocolate chip.

Find the P-value that would be used to determine if the percentage of customers who prefer mint chocolate chip ice has increased at a 5% level of significance.

P-value: Round your answer to four decimal places as necessary.

Question 18

An alternative or research hypothesis is usually the hypothesis a researcher wants to prove.

True

False

Question 19

If a null hypothesis about a population mean is rejected at the 0.025 level of significance, then it must also be rejected at the 0.01 level.
True
False

Question 20

The probability of making a Type I error and the level of significance are the same.
True
False