Statistics Review Normal Distribution

If this is the graph of data normally distributed with a mean of 30 and a standard deviation of 5, what label (number) is written at the blue circle?

• 20

• 15

• 40

• 30

The normal curve is symmetrical about the mean.

• True

• False

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

• 25%

• 68%

• 95%

• 99.7%

According to the empirical rule, how much of the data falls within 2 standard deviations of the mean?

• 25%

• 68%

• 95%

• 99.7%

The area under the normal curve is 1.

• True

• False

Which is NOT true about the normal distribution curve?

• It is bell-shaped.

• The mean, median, and mode are approximately equal

• The smaller the standard deviation, the less spread in the curve.

• It is asymmetrical.

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

• 25%

• 68%

• 95%

• 99.7%

Which best describes the shaded part of this normal distribution graph?

• All data that is one or higher.

• All data that is one or more standard deviations above the mean.

• All data that is between 1 and 3.

• All data that is above the mean.

Use the following information and the Empirical Rule to estimate the answer.

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

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

• 68%

• 94%

• 95%

• 99.7%

Use the following information and the Empirical Rule to estimate the answer.

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

There are 500 golf members at the Mathy Country Club. How many are younger than 34?

• 16

• 80

• 100

• 150