1. The following are scores of students in their quiz: 1, 2, 3, 4, 5.

a. Compute the population mean.

b. Compute the population variance.

c. Compute the population standard deviation.

2. The following are the three scores of the students above that are randomly selected: 2, 4, 5.

a. Compute the sample mean.

b. Compute the sample variance.

c. Compute the sample standard deviation.

D. Solve each problem completely. Write your solution and answer on your paper.

1. It is known that cellular phone batteries produced by a certain factory have lifetimes that follow a normal

distribution. The average lifetime of the batteries is known to be 2.4 years with a standard deviation of 0.32

years. A random sample of size 16 will be taken.

a. Determine the mean and the standard error of the sampling distribution of the means.

b. What is the probability that a random sample of size 16 will have a sample mean greater than 2.5 years?

c. What is the probability that a random sample of size 16 will have a sample mean of less than 2.2 years?