(a) Calculate the estimate for the standard error of difference between two independent means for s12 = 13, s22 = 20, n1 = 20, andn2 = 16. (Give your answer correct to two decimal places.)
(b) Calculate the estimate for the standard error of difference between two independent means for s12 = 0.057, s22 = 0.089, n1 = 13, and n2 = 6. (Give your answer correct to four decimal places.)
(c) Calculate the estimate for the standard error of difference between two independent means for s1 = 2.2, s2 = 6.8, n1 = 18, andn2 = 15. (Give your answer correct to two decimal places.)