Normal Distributions Application

The mean number of accidents a week at a company is 6.4 with a standard deviation of 1.5.  What proportion of weeks would you expect to have more than 7 accidents?

• 0.3446

• 0.2856

• 0.4

• 0.6554

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 40 yards sprint times for a soccer team are found to be normally distributed with a mean of 5.2 seconds and a standard deviation of 0.3 seconds.  What is the z-score for a player who runs a time of 5.6 seconds?

• -1.33

• 1.33

• 0.88

• 1.02

The mean number of accidents a week at a company is 6.4 with a standard deviation of 1.5.  What proportion of weeks would you expect to have less than 5 accidents?

• 0.6915

• 0.1762

• 0.8238

• -0.93

The monthly income of 5000 workers at the Microsoft plant are distributed normally. Suppose the mean monthly income is $1250 and the standard deviation is $250.
Creating a normal distribution curve shows that the amount of workers who earn more than $1500 per month is ​ (a)  

• 800 workers

• 125 workers

• 81.5% of workers

• 97.5% of workers

What type of distribution is pictured?

• Right skewed

• Left skewed

• Random

• Normal

The data is normally distributed.  What percentage of the data is in the shaded region?

• 68%

• 34%

• 50%

• 84%

Question 28

• 1

• 2

• 3

• 4

A grading scale is set up for 1000 students' test scores. It is assumed the scores are normally distributed with a mean score of 75 and a standard deviation of 15.

If a grade of a 60 is the lowest passing score, how many students are expected to pass the test? ​ (a)  

How many students are expected to fail the test? ​ (b)  

• 840 students

• 160 students

• 84 students

• 16 students

• 877 students

• 123 students

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

• 68%

• 34%

• 17%

• 50%