POLISCI RM EXAM #2

On average, what value is expected for the t statistic when the null hypothesis is true?

0

A sample of n = 9 scores has SS = 72. What is the estimated standard error for the sample mean?

1 formula? pg.282

A sample of n = 16 scores has a mean of M = 40 and a variance of s2 = 64. What is the estimated standard error for the sample mean?

2 also on pg.282

A sample of n = 9 scores has SS = 200. What is the variance for this sample?

25 variance= SS/n-1

Which of the following is a major difference between a hypothesis test with the t statistic formula and the test with a z-score?

Answer: D a. You must calculate the sample variance (or standard deviation) for the t statistic but not for the z-score b. You must know the population variance (or standard deviation) for the z-score but not for the t statistic c. You use the unit normal table to find critical values for the z-score test but not for the t test. d. All of the other options are major differences.

If two samples are selected from the same population, under what circumstances will the two samples have exactly the same t statistic?

If the samples are the same size and have the same mean and have the same sample variance.

Which of the following is a fundamental difference between the t statistic and a z-score?

The t statistic uses the sample variance in place of the population variance.

Which of the following terms is not required when using the t statistic?

σ