AP Statistics T Tests

What test should be used?

• 2 Sample t test for difference in means

• 2 proportion z test

• Paired t test

• 1 sample z test

Mrs. Trahan claims that her students' average score on the AP exam is 3.9. A random sample of 50 of her students' scores produce a mean score of 3.1 with a standard deviation of 1.5. Does this sample show evidence that Mrs. Trahan is overstating her average score?

• With a test statistic of -3.8 which is unlikely, it seems that Mrs. Trahan may be overstating her average AP score.

• With a test statistic of -4.7 which is unlikely, it seems that Mrs. Trahan may be overstating her average AP score.

• With a test statistic of -0.53 which is not unusual and this sample does not show evidence that Mrs. Trahan is overstating her average AP score.

A sample of 25 Ohio students who have taken the ACT have a sample mean score of 21.  What is the critical value used to build a 95% confidence interval for the true mean ACT score for all Ohio students?

• 2.064

• 2.086

• 1.96

• 2.060

What interval should be used?

• 2 Proportion z interval

• 1 Proportion t interval

• 1 Proportion z interval

• Chi Square for Goodness of Fit

White blood cell counts are normally distributed with mean 7500 and variance 500. If a patient has taken 50 laboratory blood tests that have a mean of 6899.75 and a standard deviation of 393.44, does this give evidence that his white blood cell count is significantly different than normal?

• One-Sample T Test for a Mean

• One-Sample Z Test for a Proportion

• One-Sample Z Test for a Mean

• One-Sample T Test for a Proportion

• The slope decreased and the r² increased.
• The slope increased and the r² decreased.
• The slope decreased but r² remained the same.
• Both slope and r² remained the same.

Fast food is often considered unhealthy because of its high content of both fat and calories. But are the two related? The fat and calorie contents of several brands of burgers were analyze for their association between fat and calorie content. What is the name of inference use to determine if a relationship exists between these two variables?

• Z-test for a proportion

• T-test for a mean

• T-test for the slope of a regression line

• Chi square test of independence

• Z-test for a difference between two proportions

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Answer explanation

Perform a complete hypothesis test with variables, hypotheses, conditions, the test identified, standardized test statistic, p-value, and conclusion in context.