Question 1

Identify when it would be appropriate to use a parametric versus a nonparametric test.

Accepted Answer

The answer of Identify when it would be appropriate to...

Question 2

If weight in the general population is normally distributed with an average of 160 pounds and a standard deviation of 20 pounds what is the probability of selecting someone who weighs 170 or more pounds?

Accepted Answer

The answer of If weight in the general population is...

Question 3

If researchers report that the results from their study were significant,p < .05,this means that
A)if they conducted the study over they would get the same results less than 5 times in 100.
B)the results are untrustworthy.
C)we would expect the results to occur by chance less than 95 times out of 100.
D)we would expect the results to occur by chance less than 5 times out of 100.

Accepted Answer

p < .05 means that we would expect the results to occur by chance less than 5 times out of 100. This is the standard cutoff for statistical significance in most fields.

Question 4

Explain how a one-tailed hypothesis differs from a two-tailed hypothesis.

Accepted Answer

The answer of Explain how a one-tailed hypothesis differs from...

Question 5

_____ are most often used with interval or ratio data whereas _____ are most often used with ordinal or nominal data.
A)t-tests; z-tests
B)z-tests; t-tests
C)Parametric tests; nonparametric tests
D)Nonparametric tests; parametric tests

Accepted Answer

Parametric tests assume that the data is normally distributed and have equal variances, and therefore are most appropriate for interval or ratio data. Nonparametric tests do not require such assumptions and are better suited for nominal or ordinal data. T-tests and z-tests are both types of parametric tests, so A and B are incorrect. D is the opposite of the correct answer.

Question 6

If weight in the general population is normally distributed with an average of 160 pounds and a standard deviation of 20 pounds what is the probability of selecting someone who weighs 120 or less pounds?

Accepted Answer

The answer of If weight in the general population is...

Question 7

Imagine that I have a jar that contains 20 black poker chips and 40 red poker chips.What is the probability of selecting a red poker chip followed by a black poker chip?

Accepted Answer

The answer of Imagine that I have a jar that...

Question 8

A false alarm is to a(n)_____ as a miss is to a(n)_____.
A)Type I error; Type II error
B)Type II error; Type I error
C)null hypothesis; alternative hypothesis
D)alternative hypothesis; null hypothesis

Accepted Answer

A false alarm is a Type I error, which occurs when a true null hypothesis is incorrectly rejected. A miss is a Type II error, which occurs when a false null hypothesis is not rejected.

Question 9

Imagine that I have a jar that contains20 black poker chips and 40 red poker chips.What is the probability of selecting a red poker chip or a black poker chip?

Accepted Answer

The answer of Imagine that I have a jar that...

Question 10

Imagine that I have a jar that contains 20 black poker chips and 40 red poker chips.What is the probability of selecting a black poker chip?

Accepted Answer

The answer of Imagine that I have a jar that...

Question 11

Imagine that I have a jar that contains20 black poker chips and 40 red poker chips.What is the probability of selecting a red poker chip?

Accepted Answer

The answer of Imagine that I have a jar that...

Question 12

If weight in the general population is normally distributed with an average of 160 pounds and a standard deviation of 20 pounds what is the probability of selecting someone who weighs 120 or less or 170 or more pounds?

Accepted Answer

The answer of If weight in the general population is...

Question 13

Explain how Type I and Type II errors are related to false alarms and misses.

Accepted Answer

The answer of Explain how Type I and Type II...

Question 14

If a researcher decides to use the .01 level of significance rather than using the more conventional .05 level of significance,what type of error is more likely to be made? Why?

Accepted Answer

The answer of If a researcher decides to use the...

Question 15

In a recent study,researchers concluded that exercise significantly lowered stress levels.What the researchers were unaware of,however,was that several of the participants in the exercise group were also taking anti-anxiety medications.The researchers' conclusion is a(n)_____ error.
A)Type II
B)Type I
C)null hypothesis
D)alternative hypothesis

Accepted Answer

This is a Type I error because the researchers concluded that exercise significantly lowered stress levels when in fact it may have been the anti-anxiety medication that was responsible. This is an error of falsely rejecting the null hypothesis (that exercise does not lower stress levels).

Question 16

A researcher hypothesizes that children who learn to read using phonics will read better than those not taught in this manner.Identify H₀ and H_a.Is this a one- or two-tailed test?

Accepted Answer

The answer of A researcher hypothesizes that children who learn...

Question 17

When the probability of a Type I error is .05 or less,we say that we have observed _____.
A)a Type II error
B)statistical significance
C)the alternative hypothesis
D)all of the above

Accepted Answer

When we observe a probability of a Type I error of .05 or less, we say that we have achieved statistical significance. Therefore, the correct answer is B. The choice A is incorrect because a Type II error is when we fail to reject a false null hypothesis. The choice C is incorrect because alternative hypothesis refers to the hypothesis that we are trying to prove through the test. The choice D is incorrect because it includes all the options which is not appropriate in this case.

Question 18

Rejecting H₀ when we should have failed to reject it is a _____ error. A)Type I B)Type II C)null D)one-tailed

Accepted Answer

Rejecting a true null hypothesis (in this case, failing to reject H₀) is a Type I error, also known as a false positive.

Question 19

Failing to reject H₀ when we should have rejected it is a _____ error. A)Type I B)Type II C)null D)one-tailed

Accepted Answer

Failing to reject H₀ when we should have rejected it is a Type II error.

Question 20

Explain the difference between the null hypothesis and the alternative hypothesis in a study.

Accepted Answer

The answer of Explain the difference between the null hypothesis...

Quiz 7: Probability and Hypothesis Testing

Identify when it would be appropriate to use a parametric versus a nonparametric test.

If weight in the general population is normally distributed with an average of 160 pounds and a standard deviation of 20 pounds what is the probability of selecting someone who weighs 170 or more pounds?

If researchers report that the results from their study were significant,p < .05,this means that

Explain how a one-tailed hypothesis differs from a two-tailed hypothesis.

_ are most often used with interval or ratio data whereas _ are most often used with ordinal or nominal data.

If weight in the general population is normally distributed with an average of 160 pounds and a standard deviation of 20 pounds what is the probability of selecting someone who weighs 120 or less pounds?

Imagine that I have a jar that contains 20 black poker chips and 40 red poker chips.What is the probability of selecting a red poker chip followed by a black poker chip?

A false alarm is to a(n) _ as a miss is to a(n) _.

Imagine that I have a jar that contains20 black poker chips and 40 red poker chips.What is the probability of selecting a red poker chip or a black poker chip?

Imagine that I have a jar that contains 20 black poker chips and 40 red poker chips.What is the probability of selecting a black poker chip?

Imagine that I have a jar that contains20 black poker chips and 40 red poker chips.What is the probability of selecting a red poker chip?

If weight in the general population is normally distributed with an average of 160 pounds and a standard deviation of 20 pounds what is the probability of selecting someone who weighs 120 or less or 170 or more pounds?

Explain how Type I and Type II errors are related to false alarms and misses.

If a researcher decides to use the .01 level of significance rather than using the more conventional .05 level of significance,what type of error is more likely to be made? Why?

In a recent study,researchers concluded that exercise significantly lowered stress levels.What the researchers were unaware of,however,was that several of the participants in the exercise group were also taking anti-anxiety medications.The researchers' conclusion is a(n) _____ error.

A researcher hypothesizes that children who learn to read using phonics will read better than those not taught in this manner.Identify H₀ and H_a.Is this a one- or two-tailed test?

When the probability of a Type I error is .05 or less,we say that we have observed _____.

Rejecting H₀ when we should have failed to reject it is a _____ error.

Failing to reject H₀ when we should have rejected it is a _____ error.

Explain the difference between the null hypothesis and the alternative hypothesis in a study.

Quiz 7: Probability and Hypothesis Testing

Identify when it would be appropriate to use a parametric versus a nonparametric test.

If weight in the general population is normally distributed with an average of 160 pounds and a standard deviation of 20 pounds what is the probability of selecting someone who weighs 170 or more pounds?

If researchers report that the results from their study were significant,p < .05,this means that

Explain how a one-tailed hypothesis differs from a two-tailed hypothesis.

_____ are most often used with interval or ratio data whereas _____ are most often used with ordinal or nominal data.

If weight in the general population is normally distributed with an average of 160 pounds and a standard deviation of 20 pounds what is the probability of selecting someone who weighs 120 or less pounds?

Imagine that I have a jar that contains 20 black poker chips and 40 red poker chips.What is the probability of selecting a red poker chip followed by a black poker chip?

A false alarm is to a(n) _____ as a miss is to a(n) _____.

Imagine that I have a jar that contains20 black poker chips and 40 red poker chips.What is the probability of selecting a red poker chip or a black poker chip?

Imagine that I have a jar that contains 20 black poker chips and 40 red poker chips.What is the probability of selecting a black poker chip?

Imagine that I have a jar that contains20 black poker chips and 40 red poker chips.What is the probability of selecting a red poker chip?

If weight in the general population is normally distributed with an average of 160 pounds and a standard deviation of 20 pounds what is the probability of selecting someone who weighs 120 or less or 170 or more pounds?

Explain how Type I and Type II errors are related to false alarms and misses.

If a researcher decides to use the .01 level of significance rather than using the more conventional .05 level of significance,what type of error is more likely to be made? Why?

In a recent study,researchers concluded that exercise significantly lowered stress levels.What the researchers were unaware of,however,was that several of the participants in the exercise group were also taking anti-anxiety medications.The researchers' conclusion is a(n) _____ error.

A researcher hypothesizes that children who learn to read using phonics will read better than those not taught in this manner.Identify H0 and Ha.Is this a one- or two-tailed test?

When the probability of a Type I error is .05 or less,we say that we have observed _____.

Rejecting H0 when we should have failed to reject it is a _____ error.

Failing to reject H0 when we should have rejected it is a _____ error.

Explain the difference between the null hypothesis and the alternative hypothesis in a study.

_ are most often used with interval or ratio data whereas _ are most often used with ordinal or nominal data.

A false alarm is to a(n) _ as a miss is to a(n) _.

A researcher hypothesizes that children who learn to read using phonics will read better than those not taught in this manner.Identify H₀ and H_a.Is this a one- or two-tailed test?

Rejecting H₀ when we should have failed to reject it is a _____ error.

Failing to reject H₀ when we should have rejected it is a _____ error.