11.04 & 11.05 Quiz

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

• 67%

• 65%

• 72%

• 68%

Using the empirical rule, what is the percentage of data that falls within two standard deviations of the mean?

• 68%

• 99.7%

• 95%

• 98%

What is the percentage of data that falls within three standard deviations of the mean, according to the empirical rule?

• 99.7%

• 98.7%

• 95%

• 100%

Using the Empirical Rule:

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%

500 juniors at Central High School took the ACT last year. The scores were distributed normally with a mean of 24 and standard deviation of 4. Approximately how many juniors scored between 16 and 32?

• 340

• 250

• 475

• 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 99.7% 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

What percentage of the data is between 1 and 2 standard deviations

• 34%

• 50%

• 2.35%

• 13.5%

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%

2000 freshmen at State Univ. took a Biology test. The scores were distributed normally with μ=70 and σ=5.

What percent of scores are less than 70?

• 34%

• 50%

• 16%

• 84%

What percent of people outside of 3 standard deviations of the mean?

• 13

• .15

• 157

• .3