Question

Suppose x has a distribution with μ = 17 and σ = 9.(a) If a random sample of size n = 45 is drawn, find μx, σ x and P(17 ≤ x ≤ 19). (Round σx to two decimal places and the probability to four decimal places.)μx =

σ x =

P(17 ≤ x ≤ 19) =

(b) If a random sample of size n = 72 is drawn, find μx, σ x and P(17 ≤ x ≤ 19). (Round σ x to two decimal places and the probability to four decimal places.)μx =

σ x =

P(17 ≤ x ≤ 19) =

(c) Why should you expect the probability of part (b) to be higher than that of part (a)? (Hint: Consider the standard deviations in parts (a) and (b).)

The standard deviation of part (b) is ---Select--- smaller than larger than the same as part (a) because of the ---Select--- smaller same larger sample size. Therefore, the distribution about μx is ---Select--- narrower the same wider .

  

Answer 1