AP Statistics Chapter 3

• A

• B

• C

• D

• E

What percent of people are greater than 3 standard deviations above the mean?

• .15%

• 34%

• 68%

• 2.35%

What percent of people are within 1 standard deviation of the mean?

• 99.7%

• 34%

• 68%

• 95%

What percent of people are within 2 standard deviations of the mean?

• 99.7%

• 34%

• 68%

• 95%

What percent of people are within 3 standard deviations of the mean?

• 99.7%

• 34%

• 68%

• 95%

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

Z < 1.23 = %

Z > 0.84 = %

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%

What is the median of the data?

• 200

• 100

• 90

• 140