chp 10

A large effect size is any value above .5. T/F?

TRUE

Effect size is a measure of how different two groups are from one another. T/F?

TRUE

If our sample selection was perfect, what would be the difference between the sample and population averages? a. zero b. one c. one or greater d. less than one

a. zero

How many groups are compared in a one-sample Z-test? a. 2 or more b. 1 c. 3 d. 4

b. 1

In the statement, z = 1.42, p > .05, which of the following interpretations is true? a. There is a significant difference between the sample value and the population. b. There is a marginally significant difference between the sample value and the population. c. There is not a significant difference between the sample value and the population. d. The answer cannot be determined from the information given.

c. There is not a significant difference between the sample value and the population.

In the formula for calculating a z score, what does SEM stand for? a. standard error of the medium b. standard ease of the mean c. standard error of the mean d. standard ease of the medium

c. standard error of the mean

The_______ is used as the denominator in the equation for the z value in a one-sample Z-test. a. standard error of the median b. standard error of the population c. standard error of the mean d. standard error of the sample

c. standard error of the mean

In the formula for calculating a z score, what does μ stand for? a. the obtained value b. the critical value c. the population average d. the sample average

c. the population average

In the effect size formula, what does μ stand for? a. the sample mean b. effect size c. the population mean d. the population standard deviation

c. the population mean

According to your text, there are five steps that you should follow in order to compute and interpret a Z-test statistic manually T/F?

FALSE

If you're comparing the test scores between two classrooms, you should use a one-sample Z-test T/F?

FALSE

SPSS does not offer a one-sample t-test. T/F?

FALSE

Sample size is taken into account when computing effect size T/F?

FALSE

The level of risk associated with the null hypothesis is generally set at _______. a. .05 b. .10 c. .001 d. .20

a. .05

The null hypothesis in a one-sample Z-test would be represented as follows: a. H_0 ∶X ̅= μ b. H_1 ∶X ̅= μ c. H_0 ∶X ̅> μ d. H_0 ∶X ̅< μ

a. H_0 ∶X ̅= μ

An alternative hypothesis in a one-sample Z-test could be represented as follows: a. H_1 ∶X ̅ >μ b. H_0 ∶X ̅>μ c. H_0 ∶X ̅= μ d. H_0 ∶X ̅<μ

a. H_1 ∶X ̅ >μ

If you have a sample size of 16 and a population standard deviation of 40, what is your standard error of the mean? a. −10 b. 10 c. 5 d. −5

b. 10

If you have a population standard deviation of 18 and a sample size of 81, what is your standard error of the mean? a. −3 b. 2 c. 1 d. 9

b. 2

If your sample mean is 20, your population average is 10, and your standard error of the mean is 2, what is your observed z value? a. −5 b. 5 c. 0 d. 50

b. 5

After conducting a one-sample Z-test, you arrived at a value of 0.2 for the z value. What is your conclusion? a. reject the null hypothesis b. accept the null hypothesis c. the result is too close to call d. None of these

b. accept the null hypothesis

If the obtained value is not higher than the critical value, we ______. a. reject the null hypothesis b. accept the null hypothesis c. accept all hypotheses d. reject all hypotheses

b. accept the null hypothesis

In the effect size formula, what does d stand for? a. the sample mean b. effect size c. the population mean d. the population standard deviation

b. effect size

In the formula for calculating standard error of the mean, what does n stand for? a. the population average b. the sample size c. the population size d. the sample average

b. the sample size

If your sample mean is 10, your population average is 15, and your standard error of the mean is 10, what is your observed z value? a. 2.5 b. −0.5 c. −2 d. 2

b. −0.5

If you have a population standard deviation of 2 and a sample size of 9, what is your standard error of the mean? a. 0.76 b. −0.67 c. 0.67 d. −0.76

c. 0.67

If you have a population standard deviation of 9 and a sample size of 81, what is your standard error of the mean? a. −3 b. 2 c. 1 d. 9

c. 1

If your population average is 45, your sample mean is 50, and your standard error of the mean is 5, what is your observed z value? a. 0 b. −.1 c. 1 d. −1

c. 1

If your sample mean is 100, your population average is 90, and your standard error of the mean is 10, what is your observed z value? a. 0 b. −.1 c. 1 d. −1

c. 1

. In z = 2.56, p < .05, what is the obtained value? a. .05 b. < .05 c. 2.56 d. 2.56 ÷ .05

c. 2.56

If your sample mean is 30, your population average is 10, and your standard error of the mean is 5, what is your observed z value? a. 6 b. −2.5 c. 4 d. 20

c. 4

A one-sample Z-test can be used to compare the mean of two samples. T/F?

FALSE

According to your text, there are eight steps that you should follow in order to compute and interpret a Z-test statistic manually. T/F?

TRUE

SPSS does not offer a one-sample Z-test. T/F?

TRUE

The results of both one-sample Z- and t-test are basically the same. T/F?

TRUE

In the statement z = 3.14, p < .05, which of the following interpretations is true? a. There is a significant difference between the sample value and the population. b. There is a marginally significant difference between the sample value and the population. c. There is not a significant difference between the sample value and the population. d. The answer cannot be determined from the information given.

a. There is a significant difference between the sample value and the population.

In t-test, if the resultant t value is -2.72 and p<.05, what is the interpretation? a. There is a statistical significance in the test. b. There is no statistical significance in the test. c. unknown d. not sure

a. There is a statistical significance in the test

In t-test, if the resultant t value is 2.72 and p<.05, what is the interpretation? a. There is a statistical significance in the test. b. There is no statistical significance in the test. c. unknown d. not sure

a. There is a statistical significance in the test.

The standard error of the mean is the best estimate that we can come up with given that it is impossible to compute ______. a. all of the possible means b. all of the possible standard deviations c. all of the possible variances d. all of the possible medians

a. all of the possible means

The one-sample Z-test is used to compare the _______ to the _______. a. mean of a sample, mean of a population b. mean of a population, mean of a sample c. mean of a sample, mean of a second sample d. mean of a population, mean of a second population

a. mean of a sample, mean of a population

For the t-test, the population's standard deviation is ______. a. not known b. known c. not relevant d. not sure

a. not known

In z = 2.56, p < .05, what is the probability? a. p < .05 b. 2.56 c. z = 2.56 d. There is no probability here.

a. p < .05

After conducting a one-sample Z-test, you arrived at a value of 5.7 for the z value. What is your conclusion? a. reject the null hypothesis b. accept the null hypothesis c. the result is too close to call d. one of these

a. reject the null hypothesis

After conducting a one-sample Z-test, you arrived at a value of −12.5 for the z value. What is your conclusion? a. reject the null hypothesis b. accept the null hypothesis c. the result is too close to call d. none of these

a. reject the null hypothesis

If the obtained value is higher than the critical value, we ______. a. reject the null hypothesis b. accept the null hypothesis c. reject the research hypothesis d. cannot determine what to do

a. reject the null hypothesis

In interpreting effect size, what is the meaning of effect size at 0.2? a. small effect size b. medium effect size c. large effect size d. weak effect size

a. small effect size

The _______ is the standard deviation of all possible means selected from the population. a. standard error of the mean b. standard error of the median c. standard error of the population d. standard error of the sample

a. standard error of the mean

The numerator of the equation for the z value is ______. a. the population average subtracted from the mean of the sample b. the mean of the sample subtracted from the population average c. the mean of the sample subtracted from the standard error of the mean d. the standard error of the mean added to the mean of the sample

a. the population average subtracted from the mean of the sample

The standard error of the mean is calculated as ______. a. the population standard deviation divided by the square root of the size of the sample b. the population standard deviation divided by the size of the sample c. the square root of the size of the sample divided by the population standard deviation d. the sample standard deviation divided by the size of the sample

a. the population standard deviation divided by the square root of the size of the sample

In the effect size formula, what does X bar stand for? a. the sample mean b. effect size c. the population mean d. the population standard deviation

a. the sample mean

If your sample mean is 12, your population average is 19, and your standard error of the mean is 4, what is your observed z value? a. −1.75 b. 5 c. 4 d. 6

a. −1.75

If you have a population standard deviation of 9 and a sample size of 144, what is your standard error of the mean? a. 7.5 b. 0.75 c. 12 d. 8

b. 0.75

If you have a population standard deviation of 20 and a sample size of 4, what is your standard error of the mean? a. −10 b. 10 c. 5 d. −5

b. 10

For the Z-test, the population's standard deviation is ______. a. not known b. known c. not relevant d. not sure

b. known

In interpreting effect size, what is the meaning of effect size at 0.3? a. small effect size b. medium effect size c. large effect size d. weak effect size

b. medium effect size

In interpreting effect size, what is the meaning of effect size at 0.4? a. small effect size b. medium effect size c. large effect size d. weak effect size

b. medium effect size

SPSS does not offer a ______. a. one-sample t-test b. one-sample Z-test c. one-sample F-test d. one-sample Chi-square test

b. one-sample Z-test

The level of risk—or level of significance—is determined by the _______. a. participants b. researchers c. study sponsors d. results

b. researchers

Calculating the one-sample Z-test serves to give you _______. a. the critical value b. the obtained value c. the level of significance d. power

b. the obtained value

If you have a population standard deviation of 18 and a sample size of 9, what is your standard error of the mean? a. −3 b. 11 c. 6 d. 5

c. 6

If you have a sample size of 4 and a population standard deviation of 12, what is your standard error of the mean? a. −3 b. 11 c. 6 d. 5

c. 6

If your sample mean is 11, your population average is 17, and your standard error of the mean is 3, what is your observed z value? a. 14 b. 8 c. −2 d. 2.2

c. −2

If your sample mean is 25, your population average is 20, and your standard error of the mean is 8, what is your observed z value? a. 1.5 b. 3 c. −5 d. 0.63

d. 0.63

. If you have a population standard deviation of 7 and a sample size of 100, what is your standard error of the mean? a. −3 b. 7 c. 10 d. 0.7

d. 0.7

If your sample mean is 25, your population average is 5, and your standard error of the mean is 10, what is your observed z value? a. 5 b. 2.5 c. −2 d. 2

d. 2

If you have a population standard deviation of 18 and a sample size of 36, what is your standard error of the mean? a. −3 b. 7 c. 10 d. 3

d. 3

. If you have a population standard deviation of 10 and a sample size of 4, what is your standard error of the mean? a. −5 b. 14 c. 6 d. 5

d. 5

After the z value is calculated, the _______ is gathered from a table of z scores. a. obtained value b. test value c. calculated value d. critical value

d. critical value

In the effect size formula, what does σ stand for? a. the sample mean b. effect size c. the population mean d. the population standard deviation

d. the population standard deviation

In the formula for calculating a z score, what does σ stand for? a. standard error of the mean b. the z value c. the sample standard deviation d. the population standard deviation

d. the population standard deviation

The denominator in the equation for the z value is equal to ______. a. the population average subtracted from the mean of the sample b. the mean of the sample subtracted from the population average c. the standard error of the mean subtracted from the population average d. the standard error of the mean

d. the standard error of the mean