Mat 143 Statistics Empirical Rule

The center of the curve represents what value of a data set?

• μ
• δ
• Σ
• Ζ

What is the percentage of data that falls within two standard deviations of the mean?

• 68%

• 95%

• 99.7%

• 67%

• 65%

• 72%

• 68%

Scores on a certain standardized test have a mean of 500, and a standard deviation of 100. How common is a score between 600 and 700? Calculate the probability.

• 2.5%

• 2.35%

• 16%

• 13.5%

Scores on a certain standardized test have a mean of 500, and a standard deviation of 100. How common is a score between 200 and 700? Calculate the probability.

• 99.7%

• 95%

• 97.35%

• None of the Above

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

• 99.7

• 34

• 68

• 95

At a local high school, GPA's are normally distributed with a mean of 2.9 and standard deviation of 0.6. What is the GPA of the highest 2.5% of the students?

• 4.1 
• 4.1 or higher
• 4.7
• 4.5 or higher

At a local high school, GPA's are normally distributed with a mean of 2.9 and standard deviation of 0.6. What percentage of students at the high school have a GPA between 2.3 and 3.5?

• 68%
• 99.7%
• 95%
• 84%

The mean life of a tire is 30,000 km. The standard deviation is 2000 km.

Then, 68% of all tires will have a life between ___________ km and __________ km.

•  28,000 km and 32,000 km.
• 24,000 km and 34,000 km.
• 26,000 km and 34,000 km.
• 27,000 km and 31,000 km.

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%