The medical records of infants delivered at Kaiser Memorial Hospital show that the infants' lengths at birth (in inches) are normally distributed with a mean of 22 and a standard deviation of 2.1. Find the probability that an infant selected at random from among those delivered at the hospital measures the following.

Question

The medical records of infants delivered at Kaiser Memorial Hospital show that the infants' lengths at birth (in inches) are normally distributed with a mean of 22 and a standard deviation of 2.1. Find the probability that an infant selected at random from among those delivered at the hospital measures the following. 
A)more than 24 in.

Steve · Answer

from your handy Z table, you find that 24 is 2/2.1 = 0.952 std above the mean P(Z>0.952) = 0.17 See the app at http://davidmlane.com/hyperstat/z_table.html