Ch2 Normal Distributions old

Which is the formula for standardized values given in your text?

• 

What is a z-score?

• relative size of mean

• percent under a density curve

• area of a density curve

• number of standard deviations

On one test, your class achieved an average grade of 80 with a standard deviation of 8 points. If you got a 96, what's your z-score?

• 16

• 2

• -2

• 20

Tags

CCSS.HSS.ID.A.4

What is the z-score of the mean of a distribution?

• 1

• 0

• there is not enough information

• I'm really not sure

Answer explanation

The mean of a distribution has a z-score of zero because z-scores are calculated by subtracting the mean from a value. If you subtract the mean from the mean, you get zero.

Tags

CCSS.HSS.ID.A.4

What is the value of a z-score if it is 2 standard deviations above the mean?

• 1

• 2

• there is not enough information

• I'm really not sure

Answer explanation

z-scores represent the number of standard deviations from the mean. If you are 2 standard deviations above the mean, then the z-score is 2.

Tags

CCSS.HSS.ID.A.4

What value of z-score represents something that is unusual?

• >3

• >0.3

• >0.03

• >1

• I'm really not sure

• z-score

• standard deviation

• mean

• median

• I'm really not sure

A standard Normal model can be described with:

• N(120,30)

• N(0,1)

• N(1,0)

• there is no standard Normal

• I'm really not sure

How can you check the Nearly Normal Condition mentioned in the book?

• make a histogram

• calculate the mean

• make a scatter plot

• all data is Normal

• I'm really not sure

Tags

CCSS.HSS.ID.A.1

CCSS.HSS.ID.A.4

Normal models are appropriate for what kind of distributions?

• Skewed with outliers

• Uniform

• Multimodal

• Unimodal and roughly symmetric

Tags

CCSS.HSS.ID.A.3

CCSS.HSS.ID.A.4