Statistics Normal Calculations

The weights of paper discarded each week by households are normally distributed with a mean of 9.43 pounds and a standard deviation of 4.17 pounds.  What percent of households discard between 10 and 12 pounds? 

• 17.68%

• 6.50%

• 28.55%

• 82.32%

The weights of paper discarded each week by households are normally distributed with a mean of 9.43 pounds and a standard deviation of 4.17 pounds.  What percent of households throw out fewer than 2 pounds of paper each week?

• 96.26%

• 48.13%

• 3.74%

• 1.87%

The weights of paper discarded each week by households are normally distributed with a mean of 9.43 pounds and a standard deviation of 4.17 pounds.  How much paper do the top 10% of households discard? 

• 16.29 pounds

• 4.09 pounds

• 14.77 pounds

• 2.57 pounds

Heights of women are normally distributed with a mean of 63.6 inches and a standard deviation of 2.5 inches.  The Beanstalk Club, a social organization for tall people, has a requirement that women must be at least 70 inches tall. What percentage of adult women meets the requirement to join the club?

• 0.52%

• 5%

• 99.48%

• 95%

The heights of male students are Normally distributed with mean 1.7 m and standard deviation 0.2 m

In a population of 400 male students, how many would you expect to have a height between 1.4 m and 1.6 m?

• 24

• 54

• 97

• 100

The commuting time for a student to travel from home to a college campus is normally distributed with a mean of 30 minutes and a standard deviation of 5 minutes. If the student leaves home at 8:25 am, what is the probability that the student will arrive at the college campus later than 9 am?

• 0.16

• 0.32

• 0.50

• 0.84

• 1.00

A data set has a normal distribution with a mean of 4800 grams and a standard deviation of 200 grams. A value from the data set is randomly chosen. What is the probability that the value is 5140 grams or less? Use the standard normal table.

Mathematical Equivalence

ON

The ages of the population of people living in Meru area in Ipoh are Normally distributed with mean 43 and standard deviation 14

The town has a population of 5,000.

How many would you expect to be aged between 22 and 57?

You can use this Standard Normal Distribution curve:

• 1750

• 3860

• 3870

• 4330

The weights of chocolate truffles made by a candy shop are approximately normally distributed with a mean of 2 ounces and a standard deviation of 0.3 ounce. What is the probability that a randomly selected chocolate truffle from this candy shop will weigh less than 1.5 ounces? The candy shop assembles gift boxes that contain 8 randomly selected chocolate truffles. What is the probability that none of the truffles in a gift box weighs less than 1.5 ounces? The weights of gift boxes, including all packaging materials, are approximately normally distributed with a mean of 3 ounces and a standard deviation of 0.5 ounce. If 8 randomly selected chocolate truffles are placed into a randomly selected gift box, describe the distribution of the total weight of the gift box and truffles.

Le the random variable X represent the amount of money Carl makes tutoring statistics students in the summer.  Assume that X is Normal with mean $240 and standard deviation $60.  The probability is approximately 0.6 that, in a randomly selected summer, Carl will make less than about

• $144

• $216

• $255

• $30