Question

The average price of a college math textbook is $175 and the standard deviation is $27. Suppose that 15 textbooks are randomly chosen. Round all answers to 4 decimal places where possible. a. What is the distribution of x? - NI b. For the group of 15, find the probability that the average price is between $171 and $177. c. Find the first quartile for the average textbook price for this sample size. S (round to the nearest cent) d. For part b), is the assumption that the distribution is normal necessary? Yes No Hint: Some Helpful Videos: . Finding the Sampling Distribution Finding a Probability Using the Central Limit Theorem Finding a Sample Mean Given its Percentile

Answer 1

8 = z box0.6745 = 175 - 27 x 0,6745 Si = 156.7075 First quartile for average text book price for sample size i $ 1156:7075 d) yes assumption that distribetion is normal is necessary, because n< 30 Therefore we can not apply central limit theorem set and say that distributi -on of is normal, As long as n.230 i we need to assume that parent population on normal