Consumers spend an average mean of $21 per week in cash without being aware of where it goes. Assume that the amount of cash spent without being aware of where it goes is normally distributed and that the standard deviation is $5. For a consumer selected at random:

a. What is the probability that a randomly selected person will spend more than $25?

b. What is the probability that a randomly selected person will spend less than $20?

c. Find the standard error of the mean for a sample of 64 people.

d. Find the probability that the average amount of cash spent without being aware of where it goes for a sample of 64 people is between $20 and $22.

having problems with c and d