## Scores on a college entrance examination are normally distributed with a mean (µ) of 500 and a standard deviation (σ) of 100. One college gives priority acceptance to students scoring above 650. What percentage of students is eligible for priority acceptance?

– HOMEWORK ASSIGNMENT #2

Name: ___________________

1. Scores on a college entrance examination are normally distributed with a mean (µ) of 500 and a standard deviation (σ) of 100.  One college gives priority acceptance to students scoring above 650.  What percentage of students is eligible for priority acceptance?

• Assume that weights of newborn children are normally distributed with a mean (µ) of 116 ounces and a standard deviation (σ) of 12 ounces.  Find the upper and lower limits that separate the top 5% and the bottom 5%.

• On one I.Q. test, the mean score (µ) is 100 and the population standard deviation (σ) is 15.  A sample of 50 scores is selected from a very large population.  Find the probability that the mean of the sample group is more than 103.

• The manager of Cardinal Electric’s light bulb division must estimate the average number of hours that a light bulb made by each light bulb machine will last.  A sample of 40 light bulbs was selected from machine A and the average burning time (x̄̄) was 1,416 hours.  The standard deviation (σ) of burning time is known to be 30 hours.  Construct a 90 percent confidence interval for the true population mean.