Question [3]: Extensive data, including that the number ofactivities per week

can be modeled as a normal distribution with mean 2and standard deviation 0.64.

(a) If a random sample of size 16is selected, what is the probability that the sample mean will

lie between 1.2 and 2.8 ?

(b) With a sample size of25 , what is the probability that the sample mean will lie

between 1.2 and 2.8 ?

Question [4]: In a large scale statewide survey concerning television viewing by

children, about 60% of the babies a few months old were reported to watch TV regularly.

In a future random sample of 300 babies in this age group, let X be the number who

regularly watch TV. Approximate the probability that

(a) X is between 185 and 190 both inclusive.(b) X is greater than 160.