Suppose Xi (i > 1) are independent identically distributed random variables with unknown mean and unknown variance, and 71 points are sampled. If the standard error of the mean is 20 for this sample size, what is the standard error of the mean for n - 639? The standard error of the mean for n - 639 is approximately Calculator Overview standard . function logic vector abc unit W P O 14.C Clear ~ Do (fro ") E ASUS VivoBook F2 F3 F4 F5 FO F7 8 FO F10 FT F12 CO. La Prt Sc Insert 70