Q1) Business wishes to evaluate true mean annual income of its customers. Business requires to be within $500 of true mean. Business estimates true population standard deviation is around $2,300. If confidence level is 95%, determine required sample size to meet desired accuracy.

Q2) Area under a normal curve with mu = 15 and sigma = 2 is

A) None of these

B) 0

C) 2

D) 1

Q3) If Sam gets a 70 on a physics test where mean is 65 and standard deviation is 5.8, where does he stand in relation to his classmates?

Q4) Area to left of "z" is .9976. What z score corresponds to this area?

Q5) According to Central Limit Theorem, how big of sample is essential to be sure sampling distribution of sample means is normally distributed, if we know underlying population is already normally distributed?