Ested in A variable of two populations has a mean of 20 and a standard deviation of 12 for one of the populations and a

[answerhappygod]

Ested In A Variable Of Two Populations Has A Mean Of 20 And A Standard Deviation Of 12 For One Of The Populations And A 1 (51.52 KiB) Viewed 23 times

Ested in A variable of two populations has a mean of 20 and a standard deviation of 12 for one of the populations and a mean of 20 and a standard deviation of 15 for the other population. Moreover, the variable is normally distributed on each of the two rate populations. Complete parts (a) through (c). and 122 al and a. For independent samples of size 9 and 25, respectively, determine the mean and standard deviation of X, -X. The mean of xy - xy is (Type an integer or a decimal. Do not round.) The standard deviation of xy - xy is (Round to four decimal places as needed.) b. Can you conclude that the variable X-X2 is normally distributed? Explain your answer. Choose the correct answer below. O A. Yes, since the variable is normally distributed on each of the two populations, X; - Xz is normally distributed. OB. No, since x - xy must be greater than or equal to 0, the distribution is right skewed, so cannot be normally distributed OC. No, Xy - X2 is normally distributed only if the sample sizes are large enough. OD. Yes, X - X, is always normally distributed because of the central limit theorem. c. Determine the percentage of all pairs of independent samples of sizes 9 and 25, respectively, from the two populations with the property that the difference x - xy between the sample means is between - 10 and 10.