# the quiz for the statistic

1. Assume that the Heights of men are normally distributed with a mean of 68.4 inches and a standard deviation of 2.8 inches. If 64 men are randomly selected, find the probability that they have a mean height greater than 69.4 inches?

2. The central limit theorem States that the sampling distribution of the sample mean is approximately normal under certain conditions. Which of the following is a necessary condition for the central limit theorem to be used?

A) The population size must be large (e.g at least 30)

B) The sample size must be large( at least 30)

C) The population from which we art sampling must not be normally distributed

D) The population from which we are simply must be normally distributed

3. One year distribution of salaries for professional sports players had mean $1.6 million and a standard deviation $0.9million. Suppose a sample of 100 major league players was taken. Find approximate probability that the average salary of the 100 players that year exceeded $1.1million.

4.suppose students ages follow a skewed right distribution with a mean of 24 years old and a standard deviation of five years. If we randomly sample 250 students which of the following statements about the same for distribution of the sample mean age is incorrect?

A) destiny deviation of the sample distribution is equal to five years

B) The shape of the sampling distribution is approximately normal

C) The standard deviation of the same thing distribution is equal to 5/ sqrt (250) years

D) The meaning of the sample distribution is 24 years old

5.The weight of corn chips dispense it into a 12 ounce bag by the dispensing machine has been identified as processing a normal distribution with the meaning of 12.5 ounces in a standard deviation of 0.1 ounce. Suppose 400 bags of chips are randomly selected. Find the probability that the mean weight of these 400 bags exceeds 12.6 ounces.

6.Assume that the heights of an adult Caucassian women have a meaning of 63.6 inches and a standard deviation of 12.5 inches.Assume that the height of an adult Kalpesh and woman have a mean of 63.6 inches and a standard deviation of 12.5 inches. If 100 women or is randomly selected what is the standard deviation of the sampling distribution of the sample mean?