Quiz Normal Curve and Z score

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%

Tags

CCSS.HSS.ID.A.4

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.

Tags

CCSS.HSS.ID.A.4

The distribution of heights of adult American men is approximately Normal with mean 69 inches and standard deviation 2.5 inches. Between what heights do the middle 95% of men fall? 

• 66.5-71.5
• 64-74
• 61.5-76.5
• 65-73

Tags

CCSS.HSS.ID.A.4

68% of the marks in a test are between 51 and 64

Assuming this data is normally distributed, what are the mean and standard deviation?

• Mean = 57

  S.D. = 6.5

• Mean = 57

  S.D. = 7

• Mean = 57.5

  S.D. = 6.5

• Mean = 57.5

  S.D. = 13

Tags

CCSS.HSS.ID.A.4

Find the area of the shaded region.

• 16%

• 84%

• 68%

• 34%

Tags

CCSS.HSS.ID.A.4

Find the Z-score.

Mean = 22

Standard Deviation: 3.1

x = 29

• 2.26

• 16.45

• -2.26

• 1.26

Find the z-score.

Mean = 40

Standard Deviation: 1.4

x = 42

• 1.43

• 1.28

• -1.4

• 1.24

If heights of 3rd graders follow a normal distribution with a mean of 52 inches and a standard deviation of 2.5 inches, what is the z score of a 3rd grader who is 47 inches tall? 

• -5
• -2
• 2
• 5

Tags

CCSS.HSS.ID.A.4

• 15.87%

• 15.39%

• 9.68%

• 84.61%

Tags

CCSS.HSS.ID.A.4

• 99.04%

• 0.96%

• 98.93%

• 97.68%

Tags

CCSS.HSS.ID.A.4