A repeated-measures study with a sample of n = 6 participants produces a mean difference of MDD= 4 with SS= 30. Use a two-tailed hypothesis test with = .05 to determine whether this sample provides evidence of a significant treatment effect.

t-critical	=
t	=

t Distribution

Degrees of Freedom = 21

-3.0-2.0-1.00.01.02.03.0t.5000.50000.000

Rejection of the null hypothesis; there is a significant treatment effect.

Rejection of the null hypothesis; there is not a significant treatment effect.

Failure to reject the null hypothesis; there is a significant treatment effect.

Failure to reject the null hypothesis; there is not a significant treatment effect.

Now assume that the sample standard deviation is SS = 480 and repeat the hypothesis test.

t-critical	=
t	=

Failure to reject the null hypothesis; there is a significant treatment effect.

Rejection of the null hypothesis; there is a significant treatment effect.

Rejection of the null hypothesis; there is not a significant treatment effect.

Failure to reject the null hypothesis; there is not a significant treatment effect.

Explain how sample variability influences the likelihood of finding a significant mean difference.

Low sample variability the likelihood of rejecting the null hypothesis if the null hypothesis is false.