15) When we carry out a chi-square test of independence, as the differences between the respective observed and expected frequencies decrease, the probability of concluding that the row variable is independent of the column variable

A) increases.

B) decreases.

C) may decrease or increase depending on the number of rows and columns.

D) will be unaffected.

16) In performing a chi-square goodness-of-fit test for a normal distribution, if there are 7 intervals, then the number of degrees of freedom for the chi-square statistic is ________.

A) 7 B) 4 C) 3 D)

18) A real estate company is analyzing the selling prices of residential homes in a given community. 140 homes that have been sold in the past month are randomly selected and their selling prices are recorded. The statistician working on the project has stated that in order to perform various statistical tests, the data must be distributed according to a normal distribution. In order to determine whether the selling prices of homes included in the random sample are normally distributed, the statistician divides the data into 6 classes of equal size and records the number of observations in each class. She then 18) 4 performs a chi-square goodness-of-fit test for normal distribution. The results are summarized in the following table

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