## Description

**PSY 520 Topic 7 Exercise Chapter 19 and 20**

**19.9:** A) Using the .01 level of signiﬁcance, test the null hypothesis that in the underlying population, crimes are equally likely to be committed on any day of the week.

B) Specify the approximate p -value for this test result.

C) How might this result be reported in the literature?

**19.10:** While playing a coin-tossing game in which you are to guess whether heads or tails will appear, you observe 30 heads in a string of 50coin tosses.

A) Test the null hypothesis that this coin is unbiased, that is, that heads and tails are equally likely to appear in the long run.

B) Specify the approximate p -value for this test result.

**19.13:** In 1912, over 800 passengers perished after the ocean liner T itanic col-lided with an iceberg and sank. The table below compares the survival frequencies of cabin and steerage passengers.

A) Using the .05 level of signiﬁcance, test the null hypothesis that survival rates are independent of the passengers’ accommodations (cabin or steerage).

B) Assuming a signiﬁcant c2, estimate the strength of the relationship.

C) To more fully appreciate the importance of this relationship, calculate an odds ratio to determine how much more likely a cabin passenger is to have survived than a steerage passenger.

**20.5: **A) Why might the Mann-Whitney U test be preferred to the t test for these data?

- B) Use U to test the null hypothesis at the .05 level of signiﬁcance psy 520 topic 7 exercise
- C) Specify the approximate p -value for this test result.

**20.7:** Does background music inﬂuence the scores of college students on a reading comprehension test? Sets of 10 randomly selected students take a reading comprehension test with rock, country, or classical music in the background. The results are as follows (higher scores reﬂect better com-prehension):

A) Why might the H test be ……for these data?

B) Use H to test the null hypothesis at the .05 level of signiﬁcance.

**(THREE VERSIONS)**