In: Statistics and Probability
Suppose x has a distribution with μ = 11 and σ = 3.
(a) If a random sample of size n = 39 is drawn, find μx, σx and P(11 ≤ x ≤ 13). (Round σx to two decimal places and the probability to four decimal places.)
μx = |
σx = |
P(11 ≤ x ≤ 13) = |
(b) If a random sample of size n = 66 is drawn, find
μx, σx
and P(11 ≤ x ≤ 13). (Round
σx to two decimal places and the
probability to four decimal places.)
μx = |
σx = |
P(11 ≤ x ≤ 13) = |
(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
part (a) because of the sample size. Therefore, the distribution about μx is .