The percent of calories from fat that a person in the United States consumes is normally distributed with a mean of about 36 and a standard deviation of 10. Suppose that one individual is randomly chosen.

• Let X = the percent of calories from fat

• = 36 percent

• = 10 percent

• X ~ N( 36, 10 )

The percent of calories from fat that a person in the United States consumes is normally distributed with a mean of about 36 and a standard deviation of 10. Suppose that one individual is randomly chosen. Find the probability that the percent of calories a person consumes from fat is more than 40.

Probability Statement: P(X > 40)=0.3446

Calculator steps: 2nd, DIST,normalcdf(40,1E99,36,10),Enter

The percent of calories from fat that a person in the United States consumes is normally distributed with a mean of about 36 calories and a standard deviation of 10 calories. Suppose that one individual is randomly chosen. Find the probability that the percent of calories a person consumes from fat is less than 50.

Probability statement: P(X < 50)=0.9192

Calculator steps: 2nd, DISTR,normalcdf(-1E99,50,36,10),Enter

The percent of calories from fat that a person in the United States consumes is normally distributed with a mean of about 36 calories and a standard deviation of 10 calories. Suppose that one individual is randomly chosen. Find the probability that the percent of calories a person consumes from fat is between 30 and 40.

Probability Statement: P(30 < X < 40) = 0.0.3812

Calculator steps:2nd, DISTR,normalcdf(30,40,36,10),Enter

The percent of calories from fat that a person in the United States consumes is normally distributed with a mean of about 36 calories and a standard deviation of 10 calories. Suppose that one individual is randomly chosen. Find the lower quartile of percent of calories from fat. (Find the 25th percentile.)

Let k = the 25th percentile.

Probability statement: P(X < k) = 0.25

k = 29.26 calories

Calculator steps to find k:

2nd,DISTR,invNorm(0.25,36,10), Enter