Exhibit 8-2 A Random Sample of 121 Automobiles Traveling on an Interstate

question 2

Multiple Choice

Exhibit 8-2
A random sample of 121 automobiles traveling on an interstate showed an average speed of 65 mph. From past information, it is known that the standard deviation of the population is 22 mph.
-Refer to Exhibit 8-2. If we are interested in determining an interval estimate for μ at 96.6% confidence, the Z value to use is

• A) 1.96
• B) 0.483
• C) 2.12
• D) 1.645

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Definitions:

Expected Frequencies

Predicted counts of occurrences across different categories based on a statistical model.

Chi-square Statistic

A measure used in statistics to analyze the independence of two categorical variables and assess how likely it is that any observed difference between sets occurred by chance.

Chi-square Statistic

A statistical measure used to evaluate the differences between observed and expected frequencies in one or more categories of a contingency table.