Normal Distributions Use Table

The 40 yards sprint times for a soccer team are found to be normally distributed with a mean of 5.2 seconds and a standard deviation of 0.3 seconds.  What is the z-score for a player who runs a time of 5.6 seconds?

• -1.33

• 1.33

• 0.88

• 1.02

Between what two standard deviations of a normal distribution contain 68% of the data?

• one below and one above

• two below and two above

• two below and zero

• zero and two above

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%

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

• 475

• 45

• 9500

The speeds of cars on the highway have a mean of 95 km/h with a standard deviation of 5 km/h. What percentage of cars averaged less than 85 km/h?

• .15%

• 2.35%

• 2.5%

• 18.5%

The mean life of a tire is 30,000 km. The standard deviation is 2,000 km. 68% of all tires will have a life between ______km and ______km.

• 26000 and 34000

• 28000 and 32000

• 24000 and 34000

• 22000 and 36000

A line up for tickets to a local concert had an average (mean) waiting time of 20 minutes with a standard deviation of 4 minutes. If 2000 ticket buyers were in line, how many of them would expect to wait for less than 16 minutes?

• 320

• 1550

• 100

• 30

In a factory, the weight of the concrete poured into a mold by a machine follows a normal distribution with a mean of 1150 pounds and a standard deviation of 22 pounds. Approximately 95% of molds filled by this machine will hold weights in what interval?

• 1084 to 1216 pounds 

• 1106 to 1150 pounds 

• 1106 to 1194 pounds 

• 1128 to 1172 pounds

This data is normally distributed. What percent of the data is in the shaded regions?

• 5%

• 95%

• 2.5%

• 50%

This data is normally distributed. What percent of the data is in the shaded region?

• 99.8%

• 0.3%

• 0.15%

• 50%