7. Most powerful business women in America. Consider that the data set is a normal distribution with a mean of 50 years and a standard deviation of 5 years. A powerful woman is randomly selected from the data, and her age is observed.

Question

Please calculate the probability of the woman having less than 55 years. Also calculate the probability of the woman having between 40 and 60 years, and the probability of the woman being more than 55 years old.

Answer 1

use this webpage instead of tables of normal distribution values
http://davidmlane.com/normal.html

enter:
mean: 50
SD: 5
click for the appropriate question

e.g. prob of woman being between 40 and 60,
click on "between" bubble and enter 40 and 60 to get
.9545 or 95.45%