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.

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CCSS.HSS.ID.A.4

The average waist size for teenage males is 29 inches with a standard deviation of 2 inches. 
If waist sizes are normally distributed, determine the z-score of a teenage male less than 33 inch .

• 2
• 1
• -2
• -1

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CCSS.HSS.ID.A.4

The mean temperature in Glens Falls for the month of February is 23 degrees with a standard deviation of 4.2 degrees.  What is the z-score for a temperature of 17 degrees?  

• 1 
• 1.43
• -1.43
• 11.5

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CCSS.HSS.ID.A.4

What shape is a normal distribution curve?

• Half curve
• Round curve
• Bell curve
• Square curve

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CCSS.HSS.ID.A.4

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%

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CCSS.HSS.ID.A.4

The z-score represents.....

• the amount of standard deviations a data value is above or below the mean.
• the percentile the data value is above or below the mean.
• the amount of standard deviations a data value is above or below the median.
• the percent the data value is above or below the mean.

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CCSS.HSS.ID.A.4

Find the area under the standard normal curve to the right of z = -2.67.

• 0.0869
• 0.9962
• 0.0008
• 0.1234

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CCSS.HSS.ID.A.4

Find P (-1.26 < z < 3.25). 

• 0.0047
• 0.9204
• 0.8956
• 0.4981

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CCSS.HSS.ID.A.4

P(z < 0.05)

• 0.5199
• 0.4801
• 0.6134
• 0.6846

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CCSS.HSS.ID.A.4

CCSS.HSS.MD.A.1

CCSS.HSS.MD.A.3

The monthly phone bills in a city are normally distributed with a mean of 30$ and a standard deviation of 12$. Find the x-value that correspond to z-scores of 3.17. 

• $1.80 
• $68.04
• $32.76

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CCSS.HSS.ID.A.4