normal distribution

In a survey of men in the United States (ages 20-29), the mean height was 69.6 inches with a standard deviation of 3.0 inches. Find the minimum height in the top 22%.

• 69.37 in 
• 67.58 in 
• 73.12 in 

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CCSS.HSS.ID.A.4

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 4.6 seconds?

• 0.83
• 1.07
• -2
• -1.07

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CCSS.HSS.ID.A.4

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%

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CCSS.HSS.ID.A.4

What is the the total area under the standard normal distribution curve?

• 100
• 25
• .5
• 1

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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

μ = 70 , σ = 8 , X = 50 . Find z score

• 2.5
• -2.5
• 5.2
• -5.2

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CCSS.HSS.ID.A.4

Which is NOT true about the standard normal distribution?

• It is bell-shaped.
• It is unimodal.
• The mean is 0 and the standard deviation is 1.
• It is asymmetrical.

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CCSS.HSS.ID.A.2

CCSS.HSS.ID.A.3

CCSS.HSS.ID.A.4

The height of students is normally distributed with mean 145 and variance 25.
Find k if P(X $\le$  k)=0.9582

• 153.65

• 154.65

• 155.65

• 149.79

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CCSS.HSS.ID.A.4

A continuous random variable is normally distributed with mean 145 and standard deviation is 5. Find P(136<X<140).

• 0.8054

• 0.8772

• 0.1228

• 0.1587

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CCSS.HSS.ID.A.4

In a research, 30% of heavy smokers are suffering from lung cancer. If 240 heavy smokers are chosen at random, find the probability that 70 to 91 are suffering from lung cancer.

• 0.3632

• 0.6338

• 0.00298

• 0.36022

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CCSS.HSS.ID.A.4