statistics
posted by angela .
Assume that women's heights are normally distributed with a mean given by u=64.6 in
and a standard deviation given by 0=2.8in.
a) If 1 woman is randomly selected, find the probability that her height is less than 65in.
b) If 49 women are randomly selected, find the probability that they have a mean height less than 65 in.

great webpage for your problem, just plug in the values that you have
http://davidmlane.com/hyperstat/z_table.html 
a.
z = (6564.6)/(2.8/sqrt(1))
z = 0.14
b.
z = (6564.6)/(2.8/sqrt(49))
z = 1 
Assume that women's heights are normally distributed with a mean given by mu equals 64.9 inμ=64.9 in, and a standard deviation given by sigma equals 2.7 inσ=2.7 in. Complete parts a and b.
a. If 1 woman is randomly selected, find the probability that her height is between 64.264.2 in and 65.265.2 in.
The probability is approximately
0.14650.1465. (Round to four decimal places as needed.)
b. If 6 women are randomly selected, find the probability that they have a mean height between 64.264.2 in and 65.265.2 in.
The probability is approximately