Jim tree wants to analyze another shipment of trees based on height. he knows the height of the trees is normally distributed so he can use the standard normal distribution. he measures the height of 500 randomly selected trees in his shipment. next, he calculates the mean and standard deviation of their heights. the mean is 60 inches and the standard deviation is 12 inches. now, jim uses the normal distribution table above to calculate the number of trees in each segment of the distribution.

standard deviation percentage from table number of trees out of 500
-1 to 0 (48 to 60 inches) 34.1%
0 to +1 (60 to inches) % 171
+1 to +2 (72 to 84 inches) %