A repeated-measures study with a sample of n = 16 participants produces a mean difference of Mp = 3 with a standard deviation of s=4. Use a two-tailed hypothesis test with a = .05 to determine whether this sample provides evidence of a significant treatment effect. t-critical t t Distribution Degrees of Freedom = 21 -3.0 t-critical = t = -2.0 -1.0 .5000 .5000 A n Failure to reject 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. Rejection of the null hypothesis; there is a significant treatment effect. A larger standard deviation significant difference. 0.0 0.000 Now assume that the sample standard deviation is s = 12 and repeat the hypothesis test. 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. Rejection of the null hypothesis; there is a significant treatment effect. Failure to reject the null hypothesis; there is a significant treatment effect. 1.0 Explain how the size of the sample standard deviation influences the likelihood of finding a significant mean difference. 2.0 the likelihood of finding a 3.0 X