Question 1

Suppose the p-value for your hypothesis test for a difference of two means was .001.Which of the following is an appropriate conclusion?

Accepted Answer

A) You reject the null hypothesis. 
B) If there really was no difference in the population means, we would see results as extreme as these only .1% of the time. 
C) You conclude that there is a statistically significant difference between the population means. 
D) All of the above. 
A) You reject the null hypothesis. 
B) If there really was no difference in the population means, we would see results as extreme as these only .1% of the time. 
C) You conclude that there is a statistically significant difference between the population means. 
D) All of the above. D

Question 2

Suppose your test statistic for a two-sided test for the difference in two means resulted in a standard score of 0.What would the resulting p-value be?

Accepted Answer

A) 0 
B) .5 
C) 1 
D) Not enough information to tell. 
A) 0 
B) .5 
C) 1 
D) Not enough information to tell. C

Question 3

For Questions , use the following narrative
Narrative: Math pass
"Higher math exam pass rates were observed in the group who got 10 hours of tutoring per week compared to those who didn't (87% versus 77%) (p<.05)."
-{Math pass narrative} Explain why it would have been better if they had reported the actual p-value.

Accepted Answer

because you would have known how extreme (strong) the results really were, not just how they compared to .05.

Question 4

Why is it important to remember the four steps of a hypothesis test?

Accepted Answer

A) So you can use them as a guideline to evaluate studies based on hypothesis tests. 
B) So you know what questions to ask when you are just presented with a sound byte talking about a "statistically significant result." 
C) Knowing what should be occurring behind the scenes helps you translate what you read, see, and hear, into a bigger picture. 
D) All of the above. 
A) So you can use them as a guideline to evaluate studies based on hypothesis tests. 
B) So you know what questions to ask when you are just presented with a sound byte talking about a "statistically significant result." 
C) Knowing what should be occurring behind the scenes helps you translate what you read, see, and hear, into a bigger picture. 
D) All of the above.

Question 5

Suppose you are told that "no relationship was found between two variables" or that "no difference was found between two groups." What does the researcher really mean, in terms of a hypothesis test?

Accepted Answer

the results are not

Question 6

For Questions , use the following narrative
Narrative: Math pass
"Higher math exam pass rates were observed in the group who got 10 hours of tutoring per week compared to those who didn't (87% versus 77%) (p<.05)."
-{Math pass narrative} What significance level is implied by the way the results are presented?

Accepted Answer

The answer of For Questions , use the following narrative
Narrative:...

Question 7

A p-value is calculated under the assumption that the null hypothesis is __________.

Accepted Answer

The answer of A p-value is calculated under the assumption...

Question 8

Suppose you are conducting a one-sided hypothesis test for a difference in two means (using 2 independent large samples), and you have a test statistic of +2.3, which is in the direction of the alternative hypothesis.How extreme is this value and what is your conclusion for this test?

Accepted Answer

The p-value is .01, which is pretty extr

Question 9

Even if researchers used an extremely sophisticated statistical analysis from a complicated hypothesis test and study, there is one piece of information that you'll always be able to interpret and understand.What is that piece of information?

Accepted Answer

A) The p-value. 
B) The test statistic. 
C) The design of the study/experiment. 
D) None of the above. 
A) The p-value. 
B) The test statistic. 
C) The design of the study/experiment. 
D) None of the above.

Question 10

Suppose you are examining the difference between two means, and you conduct a two-sided hypothesis test and your friend constructs a confidence interval.Assuming that both reveal that the null hypothesis should be rejected, what can the confidence interval tell you that the hypothesis test cannot?

Accepted Answer

A) The magnitude of the difference in the means. 
B) The direction of the difference in the means. 
C) How much variability there was in the observed results. 
D) All of the above. 
A) The magnitude of the difference in the means. 
B) The direction of the difference in the means. 
C) How much variability there was in the observed results. 
D) All of the above.

Question 11

The _______________ is the standardized score for the sample value when the null hypothesis is true.

Accepted Answer

The answer of The _______________ is the standardized score for...

Question 12

The p-value __________ (choose: is, is not) equal to the probability that the null hypothesis is true.

Accepted Answer

The answer of The p-value __________ (choose: is, is not)...

Question 13

Why is it preferable to choose a one-sided alternative rather than a two-sided alternative in the situation where you are only interested in results that are extreme in one direction?

Accepted Answer

A) Your p-value would be half as much as it would be for a two-sided test (assuming the test statistic is the same each time, and is in the direction of the one-sided alternative you selected.) 
B) Your results don't have to be as extreme in order to achieve statistical significance. 
C) Your conclusions can be more informative because they will have a direction associated with them. 
D) All of the above. 
A) Your p-value would be half as much as it would be for a two-sided test (assuming the test statistic is the same each time, and is in the direction of the one-sided alternative you selected.) 
B) Your results don't have to be as extreme in order to achieve statistical significance. 
C) Your conclusions can be more informative because they will have a direction associated with them. 
D) All of the above.

Question 14

What do we call a hypothesis test when the alternative hypothesis includes a possible difference in either direction?

Accepted Answer

A) A two-direction test. 
B) A two-sided test. 
C) A test that is not possible to conduct. 
D) None of the above. 
A) A two-direction test. 
B) A two-sided test. 
C) A test that is not possible to conduct. 
D) None of the above.

Question 15

Suppose you are told that "a relationship has been found between two variables" or that "a difference has been found between two groups." What does the researcher really mean, in terms of a hypothesis test?

Accepted Answer

the results are stat

Question 16

For Questions , use the following narrative
Narrative: Math pass
"Higher math exam pass rates were observed in the group who got 10 hours of tutoring per week compared to those who didn't (87% versus 77%) (p<.05)."
-{Math pass narrative} Name one issue that you would have to look into before you treat these results as credible.

Accepted Answer

any reasonable answer ok.Examp

Question 17

What is the relationship between the standard score and the p-value for a hypothesis test?

Accepted Answer

the p-value is the probability

Question 18

Suppose you suspect that a majority of the people in your neighborhood would like to start a neighborhood watch program, but you want to conduct a hypothesis test to find out.What are your null and alternative hypotheses? Use symbols and numbers, and explain your symbols in words.

Accepted Answer

Null: p = .50, where p = the proportion

Question 19

When you read the results of hypothesis tests in a newspaper, you are given very little information about the details of the test.What is often missing (name two things)?

Accepted Answer

any two reasonable answers ok.

Question 20

What does a p-value from a hypothesis test not tell you?

Accepted Answer

A) The direction of the difference or relationship (if one exists). 
B) How extreme the observed difference or relationship was. 
C) Whether or not your results are statistically significant. 
D) How likely it is to have observed these particular results (or more extreme ones) given that the null hypothesis is true. 
A) The direction of the difference or relationship (if one exists). 
B) How extreme the observed difference or relationship was. 
C) Whether or not your results are statistically significant. 
D) How likely it is to have observed these particular results (or more extreme ones) given that the null hypothesis is true.

Exam 23: Hypothesis Testingexamples and Case Studies

Suppose the p-value for your hypothesis test for a difference of two means was .001.Which of the following is an appropriate conclusion?

Suppose your test statistic for a two-sided test for the difference in two means resulted in a standard score of 0.What would the resulting p-value be?

Why is it important to remember the four steps of a hypothesis test?

Suppose you are told that "no relationship was found between two variables" or that "no difference was found between two groups." What does the researcher really mean, in terms of a hypothesis test?

A p-value is calculated under the assumption that the null hypothesis is __________.

Suppose you are conducting a one-sided hypothesis test for a difference in two means (using 2 independent large samples), and you have a test statistic of +2.3, which is in the direction of the alternative hypothesis.How extreme is this value and what is your conclusion for this test?

Even if researchers used an extremely sophisticated statistical analysis from a complicated hypothesis test and study, there is one piece of information that you'll always be able to interpret and understand.What is that piece of information?

Suppose you are examining the difference between two means, and you conduct a two-sided hypothesis test and your friend constructs a confidence interval.Assuming that both reveal that the null hypothesis should be rejected, what can the confidence interval tell you that the hypothesis test cannot?

The _______________ is the standardized score for the sample value when the null hypothesis is true.

The p-value __________ (choose: is, is not) equal to the probability that the null hypothesis is true.

Why is it preferable to choose a one-sided alternative rather than a two-sided alternative in the situation where you are only interested in results that are extreme in one direction?

What do we call a hypothesis test when the alternative hypothesis includes a possible difference in either direction?

Suppose you are told that "a relationship has been found between two variables" or that "a difference has been found between two groups." What does the researcher really mean, in terms of a hypothesis test?

What is the relationship between the standard score and the p-value for a hypothesis test?

Suppose you suspect that a majority of the people in your neighborhood would like to start a neighborhood watch program, but you want to conduct a hypothesis test to find out.What are your null and alternative hypotheses? Use symbols and numbers, and explain your symbols in words.

When you read the results of hypothesis tests in a newspaper, you are given very little information about the details of the test.What is often missing (name two things)?

What does a p-value from a hypothesis test not tell you?

The Benefits and Risks of Using Statistics

Reading the News

Measurements, Mistakes, and Misunderstandings

How to Get a Good Sample

Experiments and Observational Studies

Getting the Big Picture

Summarizing and Displaying Measurement Data

Bell-Shaped Curves and Other Shapes

Plots, Graphs, and Pictures

Relationships Between Measurement Variables

Relationships Can Be Deceiving

Relationships Between Categorical Variables

Statistical Significance for 2 2 Tables

Understanding Probability and Long-Term Expectations

Understanding Uncertainty Through Simulation

Psychological Influences on Personal Probability

When Intuition Differs From Relative Frequency

Understanding the Economic News

The Diversity of Samples From the Same Population

Estimating Proportions With Confidence

The Role of Confidence Intervals in Research

Rejecting Chancetesting Hypotheses in Research

Significance, Importance, and Undetected Differences

Meta-Analysis: Resolving Inconsistencies Across Studies

Ethics in Statistical Studies

Putting What You Have Learned to the Test

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