Percents Normal Distribution

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.

• 81.5%

• 68%

• 95%

• 84%

Use the following information and the Empirical Rule to estimate the answer.

The ages of golfers are normally distributed, with a mean of 38 and a standard deviation of 4.

Find the percentage of golfers that are between 30 and 46 years old.

• 68%

• 94%

• 95%

• 99.7%

Use the following information and the Empirical Rule to estimate the answer.

The ages of golfers are normally distributed, with a mean of 38 and a standard deviation of 4.

There are 500 golf members at the Mathy Country Club. How many are younger than 34?

• 16

• 80

• 100

• 150

The mean GPA of students in a course at UCDavis is 3.2 with a standard deviation of 0.3. What percent of students in the course have a GPA between  2.9 and 3.8? 

• 81.5%

• 47.5%

• 68%

• 95%

Given a mean of 75 and a standard deviation of 7, how many students out of 500 would score between 68 and 82

• 11

• 2

• 340

• 498

Given a mean of 75 and a standard deviation of 7, how many students out of 500 would score higher than 68?

• 11

• 12

• 420

• 250

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%

What percentage of the data is between -2 and -3 standard deviations

• 34%

• .15%

• 2.35%

• 13.5%

What percentage of the data is greater than 3 standard deviations

• 34%

• .15%

• 2.35%

• 13.5%