The manager of a campus bookstore finds that in the last hour before closing, 41 students bought two or more textbooks. Of these 4 used cash only, 5 used a financial aid voucher only, and 5 used a debit card only. Seven used a debit card and financial aid voucher and no cash; three used cash and debit card with no financial aid assistance. Sixteen students total used a debit card for a least part of their purchase, while 9 used none of those forms of payment. (a) How many students used all of cash, debit card, and financial aid voucher?
(b) Did more students use cash or financial aid vouchers?
(c) What percentage of students did not use a financial aid voucher?

the answer is b.

step-by-step explanation:

step-by-step explanation:

what is the figure? attach a picture.

irst, find the z score of a score of 80. this is given by the formula z = (x-u)/o, where x is the score, u is the mean, and o is the standard deviation. this gives

z = (80-78)/12 = 1/6 = .1667

now, find what percentile a z score of 1/6 correlates to in the normal distribution.

a z score of 1/6 = .1667 is equivalent to the 56.36th percentile of the distribution. so the probability a score is over this is 1-.5636 = .4364

the mean of a sample mean is equal to the original mean. however, the standard deviation of a sample mean is equal to the original standard deviation divided by the square root of n (sample size). so the new standard deviation is 12/sqrt(16) = 3.

the new z score is 80-78/3 = 2/3 = .667. this is equivalent to the 74.86th percentile. so the probability that the mean will be greater than this score is 1-.7486 = .2514.