Question 1

The selection of the null and alternative hypotheses always follows what the experimenter expects or wants to see.

Accepted Answer

A) True 
 B)False  False

Question 2

Consider a significance test for a null hypothesis versus a two-sided alternative with a z-test statistic.Give a value of z that will give a result significant at the 1% level but not at the 5% level.

Accepted Answer

A)  z = 1.96 
B)  z = -2.57 
C)  z = 3.98 
D)  There is no such z-value. 
A)  z = 1.96 
B)  z = -2.57 
C)  z = 3.98 
D)  There is no such z-value. D

Question 3

If a test of a hypothesis does not provide sufficient support for Ha to overturn the status quo, we can definitively say:

Accepted Answer

A)  H₀ is true. 
B)  Ha is definitely not true. 
C)  there is not enough information to conclude that Ha is more likely to be true than H₀. 
D)  we reject H₀. 
A)  H₀ is true. 
B)  Ha is definitely not true. 
C)  there is not enough information to conclude that Ha is more likely to be true than H₀. 
D)  we reject H₀. C

Question 4

A declaration, or claim, about the value of a specific population parameter is known as a(n):

Accepted Answer

A)  declarative statement. 
B)  hypothesis. 
C)  parametric inference. 
D)  nonparametric inference. 
A)  declarative statement. 
B)  hypothesis. 
C)  parametric inference. 
D)  nonparametric inference.

Question 5

The mean amount of time needed to thaw a particular frozen dinner in the microwave prior to convection cooking is claimed to be 5.5 min, with standard deviation of 0.95 min.To test if the actual thaw time is longer than this, we sample 35 frozen dinners and record the amount of time to thaw each one.The average thaw time is 5.8 min.What is the p-value from this test?

Accepted Answer

A)  0.3761 
B)  0.6239 
C)  0.9693 
D)  0.0307 
A)  0.3761 
B)  0.6239 
C)  0.9693 
D)  0.0307

Question 6

In a hypothesis test, the probability of a type II error for a given alternative parameter value is known to be 0.45.Assuming this alternative value is correct, what is the probability of correctly rejecting the null hypothesis (the power of the test)?

Accepted Answer

A)  power = 0.45 
B)  power = 0.55 
C)  power = 1 
D)  We cannot determine the power without more information. 
A)  power = 0.45 
B)  power = 0.55 
C)  power = 1 
D)  We cannot determine the power without more information.

Question 7

For a test of hypothesis on p, it is safe to assume   if:

Accepted Answer

A)  np0 ≤ 5 and n(1-p0) ≤ 5. 
B)  np0 ≤ 5 and n(1- p0) ≥ 5. 
C)  np0 ≥ 5 and n(1-p0) ≥ 5. 
D)  np0 ≥ 3 and n(1-p0) ≥ 3. 
A)  np0 ≤ 5 and n(1-p0) ≤ 5. 
B)  np0 ≤ 5 and n(1- p0) ≥ 5. 
C)  np0 ≥ 5 and n(1-p0) ≥ 5. 
D)  np0 ≥ 3 and n(1-p0) ≥ 3.

Question 8

The ______________ is the claim that is assumed to be true and believed to be true.

Accepted Answer

A)  null hypothesis 
B)  alternative hypothesis 
C)  test statistic 
D)  true hypothesis 
A)  null hypothesis 
B)  alternative hypothesis 
C)  test statistic 
D)  true hypothesis

Question 9

If the decision from a hypothesis test is to fail to reject the null hypothesis when in reality the null hypothesis is true, the test has:

Accepted Answer

A)  made a correct decision. 
B)  made a type I error. 
C)  made a type II error. 
D)  proved Ha true. 
A)  made a correct decision. 
B)  made a type I error. 
C)  made a type II error. 
D)  proved Ha true.

Question 10

Suppose you wish to investigate whether your spun tennis racquet is equally likely to land with the label facing up.Which of the following will always be true about the p-value in this situation?

Accepted Answer

A)  The p-value will increase as the sample proportion that lands "up" increases. 
B)  The p-value will decrease as the sample proportion that lands "up" increases. 
C)  The p-value will increase as the sample proportion that lands "up" gets further from 0.5. 
D)  The p-value will decrease as the sample proportion that lands "up" gets further from 0.5. 
A)  The p-value will increase as the sample proportion that lands "up" increases. 
B)  The p-value will decrease as the sample proportion that lands "up" increases. 
C)  The p-value will increase as the sample proportion that lands "up" gets further from 0.5. 
D)  The p-value will decrease as the sample proportion that lands "up" gets further from 0.5.

Question 11

A botanist creates a test of hypothesis to decide if the stem diameters for a hybrid plant are larger than those for standard plants.Standard plants have a mean stem diameter of 39 mm and a standard deviation of 4 mm.The botanist randomly samples 30 hybrid plants and records the stem diameters for each.What is the probability of a type II error if the population mean diameter of the hybrid plants is 41 mm and she assumes the standard deviation is still 4 mm? (Use α = 0.05,)

Accepted Answer

A)  0.9500 
B)  0.9999 
C)  0.1370 
D)  0.2181 
A)  0.9500 
B)  0.9999 
C)  0.1370 
D)  0.2181

Question 12

If the decision from a hypothesis test is to reject the null hypothesis when in reality the null hypothesis is true, the test has:

Accepted Answer

A)  made a correct decision. 
B)  made a type I error. 
C)  made a type II error. 
D)  proved Ha true. 
A)  made a correct decision. 
B)  made a type I error. 
C)  made a type II error. 
D)  proved Ha true.

Question 13

Another way to think about the of null hypothesis is that in the null hypothesis we assume that

Accepted Answer

A)  nothing out of the ordinary is happening. 
B)  all variations seen within the test data are due to random error. 
C)  nothing statically significant has occurred. 
D)  All the above. 
A)  nothing out of the ordinary is happening. 
B)  all variations seen within the test data are due to random error. 
C)  nothing statically significant has occurred. 
D)  All the above.

Question 14

A psychologist runs rats through a maze and records the total time it takes for them to navigate the course.The run times are normally distributed, and we believe the standard deviation of the run times is 121 sec.Calculate the p-value from a test to see if the mean run time differs from 600 sec if 20 randomly sampled rats have an average run time of 583 sec.

Accepted Answer

A)  0.5286 
B)  0.2643 
C)  0.7357 
D)  0.8883 
A)  0.5286 
B)  0.2643 
C)  0.7357 
D)  0.8883

Question 15

A statistical hypothesis is always a statement about a ________________, NOT about a ____________.

Accepted Answer

A)  parameter; statistic 
B)  statistic; parameter 
C)  nonparametric measure; statistic 
D)  random variable; fixed value 
A)  parameter; statistic 
B)  statistic; parameter 
C)  nonparametric measure; statistic 
D)  random variable; fixed value

Question 16

Which of the following is an appropriate hypothesis?

Accepted Answer

A) H₀: p = 2 versus Ha: p > 2 B) H₀: = 0.25 versus Ha: > 0.25 C) H₀: p = 0.17 versus Ha: p ≠ 0.17 D) H₀: μ = 0.17 versus Ha: p < 0.17 A) H₀: p = 2 versus Ha: p > 2 B) H₀: = 0.25 versus Ha: > 0.25 C) H₀: p = 0.17 versus Ha: p ≠ 0.17 D) H₀: μ = 0.17 versus Ha: p < 0.17

Question 17

The _______________ represents a significant difference from the current standard or existing state.

Accepted Answer

A)  null hypothesis 
B)  alternative hypothesis 
C)  test statistic 
D)  true hypothesis 
A)  null hypothesis 
B)  alternative hypothesis 
C)  test statistic 
D)  true hypothesis

Question 18

Price gouging occurs when retailers take advantage of the unfortunate circumstances of others to charge exorbitant prices for needed products.This practice frequently occurs after a significant natural disaster.Suppose an area experiences a devastating hurricane and authorities suspect price gouging occurred.The average price for a gallon of milk in the area was $2.34 prior to the hurricane.If after the hurricane a sample 10 stores finds the average price is now $3.05 with a standard deviation of $0.98, does it appear that the average price of milk increased significantly after the hurricane? State the critical value (CV), test statistic (TS), and decision from the test, and state the null hypothesis.(Use α = 0.05.)

Accepted Answer

A)  CV = 1.8331; TS = 2.29; reject H₀: there is probably no price gouging 
B)  CV = 1.8125; TS = 0.72; fail to reject H₀: there is possibly price gouging 
C)  CV = -1.8125; TS = -0.72; fail to reject H₀: there is probably no price gouging 
D)  CV = -1.8331; TS = 2.29; fail to reject H₀: there is possibly price gouging 
A)  CV = 1.8331; TS = 2.29; reject H₀: there is probably no price gouging 
B)  CV = 1.8125; TS = 0.72; fail to reject H₀: there is possibly price gouging 
C)  CV = -1.8125; TS = -0.72; fail to reject H₀: there is probably no price gouging 
D)  CV = -1.8331; TS = 2.29; fail to reject H₀: there is possibly price gouging

Question 19

A manufacturer of mosquito repellent claims that the average amount of time that its repellent is effective is at least 3.5 hr.A consumer group tests the claim using five randomly selected people.If the average time of effectiveness from the sample was 3.8 hr with a standard deviation of 0.76 hr, what is the critical value (CV), test statistic (TS), and decision for this test? (Use α = 0.025.)

Accepted Answer

A)  CV = -2.7764; TS = 0.88; fail to reject H₀ 
B)  CV = 2.7764; TS = 0.88; fail to reject H₀ 
C)  CV = 2.5706; TS = 0.39; fail to reject H₀ 
D)  CV = -2.5706; TS = -0.88; fail to reject H₀ 
A)  CV = -2.7764; TS = 0.88; fail to reject H₀ 
B)  CV = 2.7764; TS = 0.88; fail to reject H₀ 
C)  CV = 2.5706; TS = 0.39; fail to reject H₀ 
D)  CV = -2.5706; TS = -0.88; fail to reject H₀

Question 20

A large industrial customer complains to its electric supplier that the variance in voltage supplied to its facility exceeds the promised value of 255.The electric supplier takes 30 voltage measurements at differing times of the day and finds a sample variance of 244.Does the sample indicate that the population variance is significantly less than 255? State the critical value (CV), test statistic (TS), and decision from the test.(Use α = 0.10.)

Accepted Answer

A)  CV = -19.7677; TS = 27.749; fail to reject H₀ 
B)  CV = 14.2565; TS = 30.307; fail to reject H₀ 
C)  CV = 19.7677; TS = 27.749; fail to reject H₀ 
D)  CV = 39.0875; TS = 30.307; fail to reject H₀ 
A)  CV = -19.7677; TS = 27.749; fail to reject H₀ 
B)  CV = 14.2565; TS = 30.307; fail to reject H₀ 
C)  CV = 19.7677; TS = 27.749; fail to reject H₀ 
D)  CV = 39.0875; TS = 30.307; fail to reject H₀

The selection of the null and alternative hypotheses always follows what the experimenter expects or wants to see.

Consider a significance test for a null hypothesis versus a two-sided alternative with a z-test statistic.Give a value of z that will give a result significant at the 1% level but not at the 5% level.

If a test of a hypothesis does not provide sufficient support for Ha to overturn the status quo, we can definitively say:

A declaration, or claim, about the value of a specific population parameter is known as a(n):

In a hypothesis test, the probability of a type II error for a given alternative parameter value is known to be 0.45.Assuming this alternative value is correct, what is the probability of correctly rejecting the null hypothesis (the power of the test)?

For a test of hypothesis on p, it is safe to assume if:

The ______________ is the claim that is assumed to be true and believed to be true.

If the decision from a hypothesis test is to fail to reject the null hypothesis when in reality the null hypothesis is true, the test has:

Suppose you wish to investigate whether your spun tennis racquet is equally likely to land with the label facing up.Which of the following will always be true about the p-value in this situation?

If the decision from a hypothesis test is to reject the null hypothesis when in reality the null hypothesis is true, the test has:

Another way to think about the of null hypothesis is that in the null hypothesis we assume that

A statistical hypothesis is always a statement about a ____, NOT about a .

Which of the following is an appropriate hypothesis?

The _______________ represents a significant difference from the current standard or existing state.

Why Study Statistics

An Introduction to Statistics and Statistical Inference

Tables and Graphs for Summarizing Data

Numerical Summary Measures

Probability

Random Variables and Discrete Probability Distributions

Continuous Probability Distributions

Sampling Distributions

Confidence Intervals Based on a Single Sample

Confidence Intervals and Hypothesis Tests Based on Two Samples or Treatments

The Analysis of Variance

Correlation and Linear Regression

Categorical Data and Frequency Tables

Nonparametric Statistics

Filters

Exam 10: Hypothesis Tests Based on a Single Sample

The selection of the null and alternative hypotheses always follows what the experimenter expects or wants to see.

Consider a significance test for a null hypothesis versus a two-sided alternative with a z-test statistic.Give a value of z that will give a result significant at the 1% level but not at the 5% level.

If a test of a hypothesis does not provide sufficient support for Ha to overturn the status quo, we can definitively say:

A declaration, or claim, about the value of a specific population parameter is known as a(n):

In a hypothesis test, the probability of a type II error for a given alternative parameter value is known to be 0.45.Assuming this alternative value is correct, what is the probability of correctly rejecting the null hypothesis (the power of the test)?

For a test of hypothesis on p, it is safe to assume if:

The ______________ is the claim that is assumed to be true and believed to be true.

If the decision from a hypothesis test is to fail to reject the null hypothesis when in reality the null hypothesis is true, the test has:

Suppose you wish to investigate whether your spun tennis racquet is equally likely to land with the label facing up.Which of the following will always be true about the p-value in this situation?

If the decision from a hypothesis test is to reject the null hypothesis when in reality the null hypothesis is true, the test has:

Another way to think about the of null hypothesis is that in the null hypothesis we assume that

A statistical hypothesis is always a statement about a ________________, NOT about a ____________.

Which of the following is an appropriate hypothesis?

The _______________ represents a significant difference from the current standard or existing state.

Why Study Statistics

An Introduction to Statistics and Statistical Inference

Tables and Graphs for Summarizing Data

Numerical Summary Measures

Probability

Random Variables and Discrete Probability Distributions

Continuous Probability Distributions

Sampling Distributions

Confidence Intervals Based on a Single Sample

Confidence Intervals and Hypothesis Tests Based on Two Samples or Treatments

The Analysis of Variance

Correlation and Linear Regression

Categorical Data and Frequency Tables

Nonparametric Statistics

Filters

A statistical hypothesis is always a statement about a ____, NOT about a .