Normal Distribution Review

What shape is a normal distribution curve?

• Half curve

• Round curve

• Bell curve

• Square curve

According to the empirical rule, what percentage of data falls within 1 standard deviation? 

• 25%

• 68%

• 95%

• 99.7%

What is the standard deviation on the graph given?

• 2

• 16

• 18

• 20

What is the mean on the graph given?

• 5

• 30

• 35

• 40

A grading scale is set up for 1000 students’ test scores. It is assumed that the scores are normally distributed with a mean score of 75 and a standard deviation of 15. Calculate the score that lies -2 standard deviation from the mean.

• 60

• 45

• 475

• 9500

In an Oreo factory, the mean mass of a cookie is given as 40 g. For quality control, the standard deviation is 2 g. If 10 000 cookies were produced, how many cookies are within 2 g of the mean?

• 3200

• 6800

• 9500

• 9750

The shelf life of a particular dairy product is normally distributed with a mean of 12 days and a standard deviation of 3 days. About what percent of the products last between 12 and 15 days?

• 34%

• 68%

• 95%

• 99.7%

The distribution above is normal. What percent lies below the curve?

• 68

• 95

• 99.7

• 100

According to the empirical rule, how much of the data falls within 3 standard deviations? 

• 25%

• 68%

• 95%

• 99.7%

The ages of golfers are normally distributed, with a mean of 38 and a standard deviation of 4.

Find the proportion of golfers that are between 30 and 46 years old.

• 68%

• 94%

• 95%

• 99.7%