Question

Independent simple random samples are taken to test the difference between the means of two populations whose standard deviations are not known, but are assumed to be equal. the sample sizes are n1 = 25 and n2 = 35. the correct distribution to use for calculating the critical value and the p-value is the

Answer 1

Given that the standard deviation of the two populations are not known and that n1 , 30, we use t-distribution to calculating the critical value.

The degree of freedom is given by n1 + n2 - 2 = 25 + 35 - 2 = 58.