...has a significant effect.? State College is evaluating a new English composition course for freshman; n = 25, = ? = 70, M = 76.
If the writing scores for the population have a standard deviation of ? = 20, does the sample provide enough evidence to conclude that the new composition course has a significant effect. Assume a two-tailed test with ? = .05.
If the writing scores for the population have a standard deviation of ? = 20, does the sample provide enough evidence to conclude that the new composition course has a significant effect. Assume a two-tailed test with ? = .05.
If the population standard deviation is ? = 10, is the sample sufficient enough to demonstrate a significant effect? Assume a two-tailed test with ? = .05.
Briefly explain why you reached different conclusions for part (a) and part (b).
By using a smaller standard deviation, all else being equal, the standard error decreased, thereby increasing the z-score.
