Normal Distributions Answers

A set of data is normally distributed with a mean of 64 and a standard deviation of 2.5. What percent of the data is in the interval 64-66.5?

Four students took a national standardized test for which the mean was 500 and the standard deviation was 100. If a student’s z-value was 1.75 on the test, what was the student’s score?

The normal curve with a mean of 0 and standard deviation of 1 is called ________________

Four students took a national standardized test for which the mean was 500 and the standard deviation was 100. Their scores were 560, 450, 640, and 530. Determine the z-value for each student.

A set of data is normally distributed with a mean of 40 and a standard deviation of 2. What percent of the data is in the interval 38-42?

A sample of restaurants in a city showed that the average cost of a glass of iced tea is $1.25 with a a standard deviation of 7¢. Three of the restaurants charge 95¢, $1.00, and $1.35. Determine the z-value for each restaurant.

Suppose the heights of adult men are normally distributed. The heights of a sample of 30 men are shown below, in inches.65, 83, 69, 67, 69, 67, 67, 72, 85, 68, 73, 65, 67 ,65, 72, 71, 67, 73, 68, 72, 61, 75, 66, 78, 65, 71, 68, 76, 67, 68.What is the mean and standard deviation of this sample?

The life expectancy (in hours) of a fluorescent tube is normally distributed with a mean 8000 and a standard deviation 1000. Find the probability that a tube lasts for more than 11000 hours.

The heights of 500 students at a local school were recorded and found to be approximated by the normal curve below. Which answer could represent the mean and standard deviation for these data?

As the SAT is used for college admissions, the GRE is used for graduate school admissions. A sample of verbal and quantitative scores from the GRE are both normally distributed, with the values of and are given below. Verbal Quantitative 470 550 121 148 Kevin scored 610 on the verbal section and 700 on the quantitative section. Use the standard deviation as a unit of measurement to compare Kevin’s verbal and quantitative scores on the GRE.