Use the tdistribution to find a confidence interval for a difference in means 1 2 given the relevant sample results. Give the best estimate for 1 2, the margin of error, the relevant degrees of freedom, and the confidence interval. Assume the results come from random samples from populations that are approximately normally distributed. A 99% confidence interval for 1 2 using the sample results x1 = 501, s1 = 115, n1 = 400, and x2 = 469, s2 = 96, n2 = 200. Note that here t = 2.601