A researcher is testing a null hypothesis that states: H0: (.1 = 50. A sample of n = 25 scores is selected and the mean is M = 55. a. Assuming that the sample variance is 52 = 100, compute the estimated standard error and the t statistic. What is the t-critical value? Is this sample sufficient to reject the null hypothesis using a two-tail test with or = .05 (yes or no)? (Write down the estimated standard error, the t-value, the t-critical value and yes or no.) b. Assuming that the sample variance is 52 = 400, compute the estimated standard error and the t statistic. What is the t-critical value? Is this sample sufficient to reject the null hypothesis using a two-tailed test with (X = .05 (yes or no)? (Write down the estimated standard error, the t-value, the t-critical value and yes or no.) c. Describe how increasing variance affects the standard error and the likelihood of rejecting the null hypothesis