please help me answer the images in the question

Suppose you conduct a study and intend to use a hypothesis test to compare the means of two independent populations. Your null hypothesis is that the two means are equal. That is, Ho: p1 = p2, or equivalently, H0: p1 p2 = 0. Following is a table of the information you gather. Assume the populations from which your samples are drawn are both normally distributed. Sample Size Sample Mean Sample Variance Sample 1 111 = 21 21 = 27.6 511'- = 20.25 Sample 2 D2 = 11 :22 = 21.5 5% = 30.25 If the population variances are known (a? = 20.89 and a; = 31.43), then the standard error of i1 i2 is Y . When conducting a hypothesis test to compare the means, the test statistic is V . The appropriate degrees of freedom to use for the Student t distribution is v If the population variances are unknown but assumed to be equal (of = 6%), then the estimated standard error of i1 i2 is V . When conducting a hypothesis test to compare the means, the test statistic is V . The appropriate degrees of freedom to use for the Student t distribution is v If the population variances are unknown, but assumed to be unequal (0% 1t 0%), then the estimated standard error of i1 i2 is V . when conducting a hypothesis test to compare the means, the test statistic is V . The appropriate degrees of freedom to use for the Student t distribution is V