Question 1

If we fail to reject H₀,

Accepted Answer

A)  we have gained support for our alternative hypothesis. 
B)  the evidence does not show that treatment was effective. 
C)  the evidence suggests that treatment was effective. 
D)  our obtained value had a low probability of occurrence. 
A)  we have gained support for our alternative hypothesis. 
B)  the evidence does not show that treatment was effective. 
C)  the evidence suggests that treatment was effective. 
D)  our obtained value had a low probability of occurrence.

Question 2

One of the founders of a society for skeptics believes that people would benefit from a more questioning attitude about various claims that people make and he has developed a course to teach such skills. A standardized skepticism assessment has a μ = 90 and a σ = 20. A sample of n = 40 is obtained from students who have taken his course and their mean is M = 99. 
a. Employ the four-step hypothesis testing procedure to determine the effectiveness of the course using a two-tailed z-test and an α = .01.
b. If a significant difference was found, determine the size of the effect.

Accepted Answer

a. Step 1:
H₀: μ = 90
H₁: μ ≠

Question 3

If the mean of a population is 25, which of the following is not a correctly stated alternative hypothesis for a z-test?

Accepted Answer

A) H₁: μ ≤ 25 B) H₁: μ > 25 C) H₁: μ ≠ 25 D) H₁: μ < 25 A) H₁: μ ≤ 25 B) H₁: μ > 25 C) H₁: μ ≠ 25 D) H₁: μ < 25

Question 4

We use hypothesis testing to

Accepted Answer

A)  estimate the characteristics of a population based on sample data. 
B)  estimate the characteristics of a sample based on information from the population. 
C)  prove the alternative hypothesis to be wrong. 
D)  prove the null hypothesis to be right. 
A)  estimate the characteristics of a population based on sample data. 
B)  estimate the characteristics of a sample based on information from the population. 
C)  prove the alternative hypothesis to be wrong. 
D)  prove the null hypothesis to be right.

Question 5

Assume zcrit = +1.65 with α = .05 and zcrit = +2.33 with α = .01. Assume further that zobt = +2.02. The correct statistical decision would be to

Accepted Answer

A)  fail to reject H₀ at both α = .05 and α = .01. 
B)  reject H₀ at both α = .05 and α = .01. 
C)  reject H₀ at α = .05 but fail to reject H₀ at α = .01. 
D)  reject H₀ at α = .01 but fail to reject H₀ at α = .05. 
A)  fail to reject H₀ at both α = .05 and α = .01. 
B)  reject H₀ at both α = .05 and α = .01. 
C)  reject H₀ at α = .05 but fail to reject H₀ at α = .01. 
D)  reject H₀ at α = .01 but fail to reject H₀ at α = .05.

Question 6

If research results support the alternative hypothesis, we would

Accepted Answer

A)  fail to reject H₀. 
B)  reject H₁. 
C)  reject H₀. 
D)  both "a" and "b" are correct. 
A)  fail to reject H₀. 
B)  reject H₁. 
C)  reject H₀. 
D)  both "a" and "b" are correct.

Question 7

Effect size indicates

Accepted Answer

A)  the magnitude of a treatment effect. 
B)  when to reject the null hypothesis. 
C)  the probability associated with our obtained sample data. 
D)  the value of zcrit. 
A)  the magnitude of a treatment effect. 
B)  when to reject the null hypothesis. 
C)  the probability associated with our obtained sample data. 
D)  the value of zcrit.

Question 8

Given zcrit = ±2.58, which of the following obtained z-values will result in rejecting H₀?

Accepted Answer

A)  -3.01 
B)  +2.54 
C)  +2.93 
D)  either "a" or "c" will reject H₀. 
A)  -3.01 
B)  +2.54 
C)  +2.93 
D)  either "a" or "c" will reject H₀.

Question 9

Which of the following alpha levels would have the lowest risk of a Type I error?

Accepted Answer

A)  .05 
B)  .02 
C)  .01 
D)  .001 
A)  .05 
B)  .02 
C)  .01 
D)  .001

Question 10

In hypothesis testing, researchers usually want to

Accepted Answer

A)  reject H₁. 
B)  obtain support for H₀. 
C)  reject H₀. 
D)  fail to reject H₀. 
A)  reject H₁. 
B)  obtain support for H₀. 
C)  reject H₀. 
D)  fail to reject H₀.

Question 11

If you are using a two-tailed z-test, ________ is divided in half.

Accepted Answer

A)  α 
B)  zcrit 
C)  σM 
D)  zobt 
A)  α 
B)  zcrit 
C)  σM 
D)  zobt

Question 12

In hypothesis testing, H₀ states that

Accepted Answer

A)  obtained differences from μ are more than chance differences. 
B)  the independent variable was effective. 
C)  the independent variable was not effective. 
D)  both "a" and "b" are correct. 
A)  obtained differences from μ are more than chance differences. 
B)  the independent variable was effective. 
C)  the independent variable was not effective. 
D)  both "a" and "b" are correct.

Question 13

If the alpha level is set at .01, then a p < .01

Accepted Answer

A)  suggests a significant result. 
B)  suggests a non-significant result. 
C)  means that we should reject H₀. 
D)  both "a" and "c" are true. 
A)  suggests a significant result. 
B)  suggests a non-significant result. 
C)  means that we should reject H₀. 
D)  both "a" and "c" are true.

Question 14

According to Jacob Cohen's guidelines for interpreting effect size, d-values that fall in the range of __________ represent a small effect.

Accepted Answer

A)  .00 to .20 
B)  .10 to .20 
C)  .20 to .49 
D)  .10 to .30 
A)  .00 to .20 
B)  .10 to .20 
C)  .20 to .49 
D)  .10 to .30

Question 15

An effect size of d = .75 is equivalent to

Accepted Answer

A)  where 75% of the sample means will fall. 
B)  a probability level of the same value. 
C)  three-fourths of the critical value. 
D)  three-fourths of a standard deviation. 
A)  where 75% of the sample means will fall. 
B)  a probability level of the same value. 
C)  three-fourths of the critical value. 
D)  three-fourths of a standard deviation.

Question 16

Which of the following alpha levels will make it more difficult to reject H₀?

Accepted Answer

A)  .001 
B)  .01 
C)  .02 
D)  .05 
A)  .001 
B)  .01 
C)  .02 
D)  .05

Question 17

The rejection region of a sampling distribution is determined by ______.

Accepted Answer

A)  H₀ 
B)  H₁ 
C)  α 
D)  z 
A)  H₀ 
B)  H₁ 
C)  α 
D)  z

Question 18

If we are using a nondirectional alternative hypothesis for a z-test with α = .05, what critical value(s) should be used for rejecting the null hypothesis?

Accepted Answer

A)  -1.96 only or +1.96 only. 
B)  +1.65 only or -1.65 only. 
C)  either ±1.96 
D)  either ±1.65 
A)  -1.96 only or +1.96 only. 
B)  +1.65 only or -1.65 only. 
C)  either ±1.96 
D)  either ±1.65

Question 19

If our obtained sample mean ended up in the rejection region of a sampling distribution,

Accepted Answer

A)  the zcrit would be greater than zobt. 
B)  the probability level would be greater than alpha. 
C)  it would have had low probability of occurrence if H₀ were true. 
D)  both "a" and "b" are correct. 
A)  the zcrit would be greater than zobt. 
B)  the probability level would be greater than alpha. 
C)  it would have had low probability of occurrence if H₀ were true. 
D)  both "a" and "b" are correct.

Question 20

Explain what is meant by Type I error. How can researchers reduce the risk of making such an error?

Accepted Answer

A Type I error is rejecting a null hypot

If we fail to reject H₀,

If the mean of a population is 25, which of the following is not a correctly stated alternative hypothesis for a z-test?

We use hypothesis testing to

Assume z_crit = +1.65 with α = .05 and z_crit = +2.33 with α = .01. Assume further that z_obt = +2.02. The correct statistical decision would be to

If research results support the alternative hypothesis, we would

Effect size indicates

Given z_crit = ±2.58, which of the following obtained z-values will result in rejecting H₀?

Which of the following alpha levels would have the lowest risk of a Type I error?

In hypothesis testing, researchers usually want to

If you are using a two-tailed z-test, ________ is divided in half.

In hypothesis testing, H₀ states that

If the alpha level is set at .01, then a p < .01

According to Jacob Cohen's guidelines for interpreting effect size, d-values that fall in the range of __________ represent a small effect.

An effect size of d = .75 is equivalent to

Which of the following alpha levels will make it more difficult to reject H₀?

The rejection region of a sampling distribution is determined by ______.

If we are using a nondirectional alternative hypothesis for a z-test with α = .05, what critical value(s) should be used for rejecting the null hypothesis?

If our obtained sample mean ended up in the rejection region of a sampling distribution,

Explain what is meant by Type I error. How can researchers reduce the risk of making such an error?

Organizing Data Using Tables and Graphs

Measures of Central Tendency

Measures of Variability

Z-Scores and Other Standard Scores

Probability and the Normal Distribution

Sampling Distribution of Means

One-Sample T-Test

Two-Sample T-Test: Independent Samples Design

Two-Sample T-Test: Related Samples Design

Confidence Interval Versus Point Estimation

One-Way Analysis of Variance

Factorial Analysis of Variance

Correlation and Regression

Chi-Square

Introduction to Statistics

Nonparametric Statistics for Ordinal Data

Filters

Exam 8: Hypothesis Testing

If we fail to reject H₀,

If the mean of a population is 25, which of the following is not a correctly stated alternative hypothesis for a z-test?

We use hypothesis testing to

Assume zcrit = +1.65 with α = .05 and zcrit = +2.33 with α = .01. Assume further that zobt = +2.02. The correct statistical decision would be to

If research results support the alternative hypothesis, we would

Effect size indicates

Given zcrit = ±2.58, which of the following obtained z-values will result in rejecting H₀?

Which of the following alpha levels would have the lowest risk of a Type I error?

In hypothesis testing, researchers usually want to

If you are using a two-tailed z-test, ________ is divided in half.

In hypothesis testing, H₀ states that

If the alpha level is set at .01, then a p < .01

According to Jacob Cohen's guidelines for interpreting effect size, d-values that fall in the range of __________ represent a small effect.

An effect size of d = .75 is equivalent to

Which of the following alpha levels will make it more difficult to reject H₀?

The rejection region of a sampling distribution is determined by ______.

If we are using a nondirectional alternative hypothesis for a z-test with α = .05, what critical value(s) should be used for rejecting the null hypothesis?

If our obtained sample mean ended up in the rejection region of a sampling distribution,

Explain what is meant by Type I error. How can researchers reduce the risk of making such an error?

Organizing Data Using Tables and Graphs

Measures of Central Tendency

Measures of Variability

Z-Scores and Other Standard Scores

Probability and the Normal Distribution

Sampling Distribution of Means

One-Sample T-Test

Two-Sample T-Test: Independent Samples Design

Two-Sample T-Test: Related Samples Design

Confidence Interval Versus Point Estimation

One-Way Analysis of Variance

Factorial Analysis of Variance

Correlation and Regression

Chi-Square

Introduction to Statistics

Nonparametric Statistics for Ordinal Data

Filters

Assume z_crit = +1.65 with α = .05 and z_crit = +2.33 with α = .01. Assume further that z_obt = +2.02. The correct statistical decision would be to

Given z_crit = ±2.58, which of the following obtained z-values will result in rejecting H₀?