Empirical Rule and Z-scores Sub Practice

By the way, what is standard deviation?

• good question
• how standardly something deviates
• average distance that data points are from the average
• Idk but I should probably find out pretty soon

Tags

CCSS.HSS.ID.A.4

CCSS.HSS.ID.A.2

CCSS.HSS.ID.A.3

Adam's Z-score on a test is +2.5.  What does this mean?

• He'd better start studying.
• He did better than EVERYONE.
• He scored 2.5 standard deviations above the average.
• He did terrible.

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CCSS.HSS.ID.A.4

Joanne's Z-score is -1.5.  What does this mean?

• She didn't take the test yet.
• She scored 1.5 standard deviations below the average.
• She did better than most people.
• No clue

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CCSS.HSS.ID.A.4

If Gonzalo's score is 87, the class average is 82, and the SD is 4, what is Gonzalo's Z-score?

• -1.25
• +1.25
• +1.20
• +1.02

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CCSS.HSS.ID.A.4

Jill's Z-score on the same test was a +3.0.  (average was 82 and SD was 4).  
What was her actual score?

• 85 %
• 79 %
• 94 %
• 40 %

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CCSS.HSS.ID.A.4

What is the Z-score for Tina if she got a 31 on the ACT, the mean was 23 and the SD was 4?

• +0.2
• +2.0
• -2.0
• -0.2

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CCSS.HSS.ID.A.4

What is the Z-score for Paula if she got 1400 on the SAT, the mean was 1100 and the SD was 275?

• -1.90
• -1.09
• +1.09
• +1.90

Tags

CCSS.HSS.ID.A.4

So if Tina's Z-score is +2.0 and Paula's Z-score is +1.09, who performed better?

• Tina's performance is farther away from the mean so she did better.
• Paula's score is closer to the mean so she did better.
• They both did the same.
• Can I take a nap now?

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CCSS.6.SP.A.3

CCSS.6.SP.B.5

All of the below sets have the same mean.
Set 1-Standard Deviation=3.1
Set 2-Standard Deviation=4.9
Set 3-Standard Deviation=1.7
Set 4-Standard Deviation=3.2
Which set of data probably has the points closest to the mean?

• 1
• 2
• 3
• 4

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CCSS.HSS.ID.A.2

Suppose that a normal model describes the acidity (pH) of rainwater, and that water tested after last week’s storm had a z-score of 1.8. This means that the acidity of the rain 

• had a pH 1.8 higher than average rainfall. 
• had a pH of 1.8. 
• varied with standard deviation 1.8 
• had a pH 1.8 standard deviations higher than that of average rainwater. 

Tags

CCSS.HSS.ID.A.4