Stats 235

What is the third quartile of the data?

• 46

• 29

• 38

• 40

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

• 68%

• 95%

• 99.7%

• 50%

Find the median, mode and range: 
3, 5, 7, 9, 11, 8, 3

• median:7  mode:3  range:7

• median:6  mode:3  range:7

• median:7  mode:3  range:8

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%

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.

Find the Inter-Quartile Range (IQR). (Hint: Q3-Q1)

• 7609

• 8924.5

• 2708

• 5416

On a recent test, one class of 26 students had a mean score of 78%, while another class of 32 students had a mean score of 86%. What is the overall mean of the two classes combined?

• 82

• 82.4

• 81

• 83

The following table shows the annual salaries earned by employees of a small company. What is the mean?

• 75,650

• 54,950

• 42,750

• 51,000

The following table shows the annual salaries earned by employees of a small company. What is the median?

• 75,650

• 54,950

• 42,750

• 51,000

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