Psychology 400-3003
Psychological Statistics
Spring 2015- Chi Square Practice
Dr. Hitlan
CORRECT ANSWERS BOLDED
1. The expected frequencies _____.
a. are always whole numbers
b. can contain fractions or decimal values
c. can contain both positive and negative values
d. can contain fractions and negative numbers
2. Ten years ago, only 15% of the U.S. population consisted of people more than 65 years old. A researcher plans to use a
sample of n = 300 people to determine whether the population distribution has changed during the past ten years. If a chi-
square test is used to evaluate the data, what is the expected frequency for the older-than-65 category?
a. 15
b. 30
c. 45
d. 150
3. A large value for the chi-square statistic indicates
a. the sample data (observed values) do not match the null hypothesis
b. there is a good fit between the sample data (observed values) and the null hypothesis
c. the observed values from the sample data are consistently larger than the expected values
d. the observed values from the sample data are consistently smaller than the expected values
4. The null hypothesis for the chi-square test for independence states that _____.
a. there is a relations between the two variables
b. there is no relation between the two variables
c. both variables have the same frequency count
d. the two variables have different frequency counts
5. A basic assumption for a chi-square hypothesis test is _____.
a. the population distribution(s) must be normal
b. the scores must come from an interval or ratio scale
c. the observations must be independent
d. All of the other choices are assumptions for chi-square.
6. A researcher is examining the relation between color preferences and gender. A sample of 30 men and 30 women is
obtained, and each person is asked to identify his/her preference between two choices of paint colors for a new student
lounge. For this sample, 5 of the men preferred color A, and 15 of the women preferred color A. If a chi-square test is
used to evaluate the relationship, what is the df value for the chi-square statistic?
a. 1
b. 3
c. 57
d. 59
7. For a fixed a level, how is the critical value for chi-square related to the size of the sample?
a. As the sample size increases, the critical value also increases.
b. As the sample size increases, the critical value decreases.
c. The critical value of chi-square is not related to the sample size.
