8)Suppose a sample of size n=20 picked from the Poisson distribution, the sample mean was found to be equal to 6. A point estimate of the variance of the estimator of population mean is: a. 6 b. 3 c. 0.55 approximately d. 0.3 9)Assuming normal distribution, a 95% prediction interval for a single future value to be selected from a normal population when a sample of size n=25 gives a sample standard deviations=3 and a sample mean = 58.3 is: a. (51.99, 64.61) b. (52.30, 64.30) c. (52.30, 64.61) d. (51.99, 64.30)