9.1 Sampling Distributions
Summary of “Post It” Activity from yesterday:
Let x denote the height of a randomly Let x denote the mean height selected female. of a random sample of 30 females. x-distribution
SAMPLING DISTRIBUTION x~ N(64.5, 2.5)
x distribution (n = 30)
Normal
x x
Parameters:
Parameters:
µx =
µx =
σx =
Q: What is the probability that a
randomly selected woman will
be taller than 63.7 inches ?
(use tables and z-calculations)
Q: If a woman is in the 90th
percentile for her height,
how tall is she ?
σx =
Q: What is the probability
that a randomly selected
sample of size n = 30 women
will have a mean height
that is greater than 63.7 in ?
Q: If a sample of n = 30 women
have an average height that
is in the 90th percentile,
what is their average height?