Date: Mar 10, 2013 4:15 PM
Subject: Help with word problems
Need help with these word problems, pretty hard.
1. Airline Delays. Suppose you are a scheduler for a major airline, analyzing a distribution of flight delays (departures) during one day at an airport. The distribution of delay times has the following properties: The mean delay is 10 minutes, the median delay is 6 minutes, the mode is the distribution is 0 minutes, and the maximum delay is 25 minutes.
a. What percentage of flights were delayed less than 6 minutes?
b. What percentage of flights were delayed more than 6 minutes?
2. Body Mass Index (BMI). The body mass indices of American men between ages 30 and 50 are normally distributed with a mean of 26.2 and a standard deviation of 4.7.
a. Determine the standard score and percentile of a BMI of 22.
b. Determine the standard score and percentile of a BMI of 28.
c. Several health organizations have declared that men with a BMI of 25 or greater are overweight and that men with a BMI of 30 or greater are obese. What percentage of American men are overweight? obese?