Finding Normal Distribution Probability

Test has a mean of 40, standard deviation of 10. What is the percent of people with a score below 37?

• 52.97%

• 31.53%

• 48.99%

• 38.21%

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?

• 1750

• 3860

• 3870

• 4330

Assume that the random variable X is normally distributed, with mean μ = 80 and standard deviation σ = 15.

Compute the probability P(X > 92).

• 0.1977

• 0.2119

• 0.7881

• 0.2420

The lengths of pregnancies of humans are normally distributed with a mean of 268 days and a standard

deviation of 15 days. Find the probability of a pregnancy lasting more than 300 days.

• 0.0166

• 0.9834

• 0.2375

• 0.3189

The distribution of cholesterol levels in teenage boys is approximately normal with μ = 170 and σ = 30 (Source:

U.S. National Center for Health Statistics). Levels above 200 warrant attention. Find the probability that a

teenage boy has a cholesterol level greater than 200.

• 0.3419

• 0.1587

• 0.8314

• 0.2138

An airline knows from experience that the distribution of the number of suitcases that get lost each week on a

certain route is approximately normal with μ = 15.5 and σ = 3.6. What is the probability that during a given

week the airline will lose less than 20 suitcases?

• 0.3944

• 0.1056

• 0.4040

• 0.8944

Assume that the salaries of elementary school teachers in the United States are normally distributed with a

mean of $32,000 and a standard deviation of $3000. If a teacher is selected at random, find the probability that

he or she makes more than $36,000.

• 0.9802

• 0.2113

• 0.0918

• 0.9827

The distribution of cholesterol levels in teenage boys is approximately normal with μ = 170 and σ = 30 (Source:U.S. National Center for Health Statistics). Levels above 200 warrant attention. What percent of teenage boyshave levels between 170 and 225?

• 46.64 %

• 3.36 %

• 6.06 %

• 56.13 %

Assume that the heights of American men are normally distributed with a mean of 69.0 inches and a standard deviation of 2.8 inches. The U.S. Marine Corps requires that men have heights between 64 and 78 inches. Find the percent of men meeting these height requirements.

• 31.12 %

• 99.93 %

• 3.67 %

• 96.26 %

The graph depicts IQ scores of adults, and those scores are normally distributed with a mean of 100 and a

standard deviation of 15. Find the probability that a member selected at random is from the shaded area of the

graph.

• 0.6293

• 0.4400

• 0.7486

• 0.8051