Question

7.510 (Video Solution) x Incorrect. A procurement specialist has purchased 27 resistors from vendor 1 and 28 resistors from vendor 2. Let X1,1, X1.2,...,X1,27 represent the vendor 1 observed resistances, which are assumed to be normally and independently distributed with mean 100 ohms and standard deviation 1.6 ohms. Similarly, let X2,1, X2,2,...,X2,28 represent the vendor 2 observed resistances, which are assumed to be normally and independently distributed with mean 105 ohms and standard deviation of 1.9 ohms. What is the sampling distribution of X -X2 ? What is the standard error of X - X2 ? The sampling distribution of Xi - X2 is NMT-v= 1.0948 1.4875 , X-X ) (Round the second answer to four decimal places.) .-2 .48 The standard error of Xi - X2 is L .488 . (Round your answer to three decimal places.) Statistical Tables and Charts

Answer 1

MX-X, = E(X1 - X2) = E(X1) - E(X2) = 100 – 105 = -4 o -19 = Var(#1 - Xx) = Var (X1) + Var (X2) = 1,0 + 1,= 0.2237 (Since X1.j and X2,; are independent) Standard error of Xi - X2 = standard deviation of Xi - X2= 0.473