Americans receive an average of 18 christmas cards each year. suppose the number of christmas cards is normally distributed with a standard deviation of 5. let x be the number of christmas cards received by a randomly selected american. round all answers to 4 decimal places where possible.


a. what is the distribution of x? x ~ n( , )


b. if an american is randomly chosen, find the probability that this american will receive no more than 21 christmas cards this year.

(round z-score up to 2 decimal places. )


c. if an american is randomly chosen, find the probability that this american will receive between 19 and 24 christmas cards this year.

(round z-score up to 2 decimal places. )


d. 82% of all americans receive at most how many christmas cards? (please enter a whole number)