A variable of two populations has a mean of 25 and a standard deviation of 30 for one of the populations and a mean of 25 and a standard deviation of 16 for the other population. Moreover, the variable is normally distributed on each of the two populations. Complete parts (a) through (c). a. For independent samples of size 25 and 4, respectively, determine the mean and standard deviation of x1 -x2 The mean of x, -x2 is o (Type an integer or a decimal. Do not round.) The standard deviation of x1 -x2 is 10.000 Round to four decimal places as needed.) Choose the correct answer below. 0 A. Yes, xi-x2 is always normally distributed because of the central limit theorem .? Yes, sice he variable is normally distributed on each of the two populations, x1-x2 is normaly distributed OC. No, since x1 -32 must be greater than or equal to 0, the distribution is right skewed, so cannot be normally distributed OD. No, x-2 is normally distributed only if the sample sizes are large enough c. Determine the percentage of all pairs of independent samples of sizes 25 and 4, respectively, from the two populations with the property that the differencex-x2 between the sample means is between -20 and 20.