Normal Deviation

The z-score represents.....

• the amount of standard deviations a data value is above or below the mean.

• the percentile the data value is above or below the mean.

• the amount of standard deviations a data value is above or below the median.

• the percent the data value is above or below the mean.

The distances male long jumpers for State College jump are approximately normal with a mean of 263 inches and a standard deviation of 14 inches.  
Suppose a male long jumper's jump ranked in the 75th percentile.  How long was his jump?

• 0.67 inch

• 263 inches

• 272.44 inches

• 277.25 inches

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?

• 68%

• 34%

• 16%

• 2.5%

Which is NOT true about the standard normal distribution?

• It is bell-shaped.

• It is unimodal.

• The mean is 0 and the standard deviation is 1.

• It is asymmetrical.

What is the the total area under the standard normal distribution curve?

• 100

• 25

• .5

• 1

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?

• 40

• 35

• 45

• 50

Given a mean of 75 and a standard deviation of 7, what percentage of scores are between 75 and 82?

• 68%

• 81.5%

• 16%

• 34%

The average weight of a newborn is 7.5 pounds, with a standard deviation of 1.25 pounds. Birth weight follows the standard normal curve. What percent of newborns weigh 5 pounds or less at birth?

• 2.35%

• 0.15%

• 2.5%

• 50%

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?

• 68%

• 34%

• 16%

• 2.5%

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

• 25%

• 68%

• 95%

• 99.7%