Deck 7: Overview of Statistical Hypothesis Testing: the Z-Test

Question 1

A nonparametric procedure would not be done in conjunction with

A)ratio distributions.
B)a skewed interval distribution.
C)computing the median.
D)computing the mode.

Answer 1

A

Question 2

Which of the following accurately defines a Type II error?

A)Rejecting when it is true
B)Rejecting when it is false
C)Failing to reject when it is true
D)Failing to reject when it is false

Answer 2

D

Question 3

How would you report a nonsignificant z-obtained value of -.50 in a journal article?

A)z = -.50, p > .05
B)z = -.50, p < .05
C)z = .50, p > .05
D)z = -.50, p > .50

Answer 3

A

Question 4

Which of the following accurately defines a Type I error?

A)Rejecting when is true
B)Rejecting when is false
C)Retaining when is true
D)Retaining when is false

Question 5

What happens to the probability of committing a Type I error if the level of significance is changed from α = .01 to α = .05?

A)The probability of committing a Type I error will decrease.
B)The probability of committing a Type I error will increase.
C)The probability of committing a Type I error will remain the same.
D)The change in probability will depend on your sample size.

Question 6

Which of the following is correct regarding alternative hypotheses?

A)They are alternatives to the experimental hypotheses.
B)They state the predicted relationship if the sample statistic does not fall in the region of rejection.
C)They describe the population parameters represented by the sample data if the predicted relationship exists.
D)They describe the population parameters represented by the sample data if the predicted relationship does not exist.

Question 7

When experimental results are significant, this means the hypothesis has been .

A)experimental; rejected
B)alternative; rejected
C)null; accepted
D)null; rejected

Question 8

Inferential statistics are used to

A)decide whether sample data represent a particular relationship in the population.
B)get rid of sampling error.
C)improve sampling error.
D)decide whether the population causes a particular relationship in the sample data.

Question 9

Which of the following is correct regarding statistical hypotheses null hypothesis and alternative hypothesis)?

A)They describe the population parameters our sample data represent if there is or is not a predicted relationship.
B)They describe the sample data if there is or is not a relationship in the population.
C)We can prove a relationship exists in the population by confirming these hypotheses.
D)They are the hypotheses we perform on the statistics in our experiment.

Question 10

Which of the following assumptions are common to all parametric statistics?

A)There are no common assumptions.
B)The population of dependent scores forms a normal distribution, regardless of what kind of scores they are.
C)The dependent scores must be interval or ratio scores, regardless of whether the population of scores forms a normal distribution.
D)The population of dependent scores a) must be interval or ratio scores and b) must form an approximately normal distribution.

Question 11

Which of the following statements does not belong

A)Our condition of the independent variable produced a significant difference in the dependent scores.
B)The change in the dependent scores was produced by significant sampling error.
C)We obtained a significant z.
D)There is a significant effect of the condition.

Question 12

Which of the following is correct regarding experimental hypotheses?

A)We can prove a predicted relationship exists in a population by confirming an experimental hypothesis.
B)They describe the population parameters to be tested by the experiment.
C)They describe the predicted relationship we may or may not find in an experiment.
D)We can prove theories about behavior by confirming experimental hypotheses.

Question 13

When is a one-tailed test used?

A)When no relationship is predicted
B)When a relationship is predicted and the direction in which the scores will change is predicted
C)When the demonstrated relationship is predicted
D)When a relationship is predicted without stating the direction in which the scores will change

Question 14

If a sample mean is different from a particular population $\mu$ , we can conclude the sample mean probably represents some other population or else

A)the sample mean does not represent the sample statistic.
B)an error was made in calculating the sample mean.
C)an error was made in calculating standard error.
D)the sample mean occurred as a result of sampling error.

Question 15

The power of a statistical test is the probability of

A)failing to reject a false .
B)failing to reject a true .
C)rejecting a false .
D)rejecting a true .

Question 16

Which is not an assumption of a z-test?

A)The dependent variable is perfectly normal and must involve an interval scale.
B)We know the mean of the population of raw scores under another condition of the independent variable.
C)We have randomly selected one variable.
D)We know the true standard deviation of the population.

Question 17

Which of the following tests is considered to be more powerful?

A)A one-tailed test
B)A two-tailed test
C)Neither; they are both equally statistically powerful
D)Which is more powerful depends on the sample size

Question 18

Which of the following is true of any one-sample experiment?

A)We must know the population mean under the same condition of the independent variable as the one being tested.
B)We must know the population mean under some condition of the independent variable other than the one being tested.
C)We must know the sample mean under the condition of the independent variable being tested, but we do not need to know the population mean.
D)We must know the sample mean under the condition of the independent variable being tested and under some other condition of the independent variable.

Question 19

When statisticians report results as nonsignificant, the results are

A)not due to chance.
B)not important.
C)not too unlikely to accept as representing the same population.
D)different from what was expected or predicted.

Question 20

What is the typical alpha level selected by researchers?

A).05
B)5
C).01
D).95

Question 21

If = -2.11 do you reject or fail to reject using a one-tailed test in the upper tail with α = .05?

Question 22

If and what is the value of ?

Question 23

Suppose you conduct an experiment, and your is statistically significant at +3.45.How would you correctly report this result?

Question 24

Given and conduct a two-tailed z-test.Use α = .05.Be sure to set up your hypotheses and rejection region, calculate your z-score, and state your decision.

Question 25

State the hypotheses for a two-tailed test against a known population mean of 90.

Question 26

Suppose you conduct an experiment, and the is statistically nonsignificant at −0.65.How would you correctly report this result?

Question 27

If you have and conduct a two-tailed z-test.Use α = .05.Be sure to set up your hypotheses and rejection region, calculate your z-score, and state your decision.

Question 28

If you have and conduct a two-tailed z-test.Use α = .05.Be sure to set up your hypotheses and rejection region, calculate your z-score, and state your decision.

Question 29

If = +2.21, do you reject or fail to reject using a two-tailed test with α = .01?

Question 30

Suppose a researcher has made a decision that a certain pill is not effective at treating depression when, in reality, it is.What has the researcher done in this case?

A)The researcher has made a Type II error.
B)The researcher has made a Type I error.
C)The researcher has made a correct decision to reject the null hypothesis.
D)The researcher has made a correct decision to reject the alternative hypothesis.

Question 31

The population mean for the Elementary Tenacity Test ETT) is 150 with A recent study of elementary school children participating in a school lunch program obtained the following ETT scores.Use a two-tailed z-test and

Question 32

If you have and conduct a two-tailed z-test.Use α = .01.Be sure to set up your hypotheses and rejection region, calculate your z-score, and state your decision.

Question 33

For and = .05, what is the appropriate outcome of a z- test?

Question 34

Given and conduct a one-tailed z-test in the upper tail.Use α = .05.Be sure to set up your hypotheses and rejection region, calculate your z-score, and state your decision.

Question 35

If = +2.21, do you reject or fail to reject using a one-tailed test in the upper tail with α = .05?

Question 36

Given and conduct a two-tailed z-test.Use α = .01.Be sure to set up your hypotheses and rejection region, calculate your z-score, and state your decision.

Question 37

If you have and conduct a one-tailed z-test for a lower mean.Use α = .05.Be sure to set up your hypotheses and rejection region, calculate your z-score, and state your decision.

Question 38

Given and conduct a two-tailed z-test.Use α = .05.Be sure to set up your hypotheses and rejection region, calculate your z-score, and state your decision.

Question 39

If the difference between your sample mean and the known population mean is 1.961, and your population standard deviation is 5, how big of a sample size would you need to get a significant result using α = .05 and a two-tailed test?

Question 40

The Physical Fitness Test National Level for Girls) shows the national average for 10­year­old girls on "right­angle push­ups" to be μ = 13.Principal Smyth hypothesizes her girls at Strong School are significantly above the national mean.If the = 6 and the scores for nine girls are as reported here, compute and determine if Principal Smyth is right.Use α = .05.
14 16 18 16 12 16 17 20 15

Question 41

If the probability that you will reject a that is false is 0.85, what is the probability you will commit a Type II error?

Question 42

To determine whether a new drug designed to lower a person's heart rate is effective or not, Dr.Johnson gives the medicine to a random sample of 100 patients with Rapid Heart Rhythm RHR) and obtains a sample mean of 128.Dr.Johnson knows the heart rate of the population of individuals with RHR is 135 with .If Dr.Johnson uses a one-tailed test and α = .05, what is the appropriate conclusion?

Question 43

If you read "z = -.33, p < .05" in a research journal, what does this mean?

Question 44

Suppose a researcher develops a drug designed to promote sleep.Those who take this drug, on average, sleep for
8.1 hours per night whereas those who do not take it sleep for 7.5 hours per night.In the context of this study, what would the null hypothesis suggest?

Question 45

Suppose a researcher develops a drug designed to promote sleep.Those who take this drug, on average, sleep for
8.1 hours per night whereas those who do not take it sleep for 7.5 hours per night.In the context of this study, what would the alternative hypothesis suggest?

Question 46

What does the statement "p < .05" tell us in regards to a Type I error?

Question 47

What are the two basic assumptions of all parametric procedures?

Question 48

What is the relationship between N and power?

Question 49

What is the difference between a significant result at the .05 level versus the .01 level?