Sarah took the advertising department from her company on a round trip to meet with a potential client. Including sarah a total of 17 people took the trip. she was able to purchase coach tickets for $310 and first class tickets for $1080. She used her total budget for airfare for the trip. which was $12200. how many first class tickets did she buy? how many coaches tickets did she buy?

ιт ιѕ 6 6/23

step-by-step explanation:

нσρє ι ¢συℓ∂ нєℓρ уσυ συт

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.