Z-Scores

Tests in Mr. Jones class have a mean score of 73 and standard deviation of 6 points. Mark scored a 68 on the test. What is his z-score?

• 0.83
• 5
• -0.83
• -5

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CCSS.HSS.ID.A.4

The weights of miniature horses are roughly normally distributed with a mean of 230 pounds and standard deviation of 45 pounds.
What proportion of miniature horses weigh between 185 and 320 pounds? 

• 68%
• 25%
• 95%
• 81.5%

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CCSS.HSS.ID.A.4

The weights of miniature horses are roughly normally distributed with a mean of 230 pounds and standard deviation of 45 pounds.
What proportion of miniature horses weigh less than 140 pounds? 

• 5%
• 2.5%
• 95%
• 10%

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CCSS.HSS.ID.A.4

The weights of miniature horses are roughly normally distributed with a mean of 230 pounds and standard deviation of 45 pounds.
What proportion of miniature horses weigh between 95 and 365 pounds? 

• 50%
• 68%
• 95%
• 99.7%

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CCSS.HSS.ID.A.2

CCSS.HSS.ID.A.4

The weights of miniature horses are roughly normally distributed with a mean of 230 pounds and standard deviation of 45 pounds.
What proportion of miniature horses weigh more than 185 pounds? 

• 68%
• 84%
• 95%
• 99.7%

The following information applies to the next 6 questions: The weights of miniature horses is roughly normally distributed with a mean of 230 pounds and standard deviation of 45 pounds.
What proportion of miniature horses weigh more than 230 pounds? 

• 45%
• 50%
• 230 horses
• 68%

Tags

CCSS.HSS.ID.A.4

Which colored curve has the lowest standard deviation?

• Orange
• Red
• Blue
• Green

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CCSS.HSS.ID.A.2

CCSS.HSS.ID.A.3

Which colored curve has the highest standard deviation?

• Orange
• Red
• Blue
• Green

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CCSS.HSS.ID.A.2

CCSS.HSS.ID.A.3

Which colored curve has the lowest mean?

• Orange
• Red
• Blue
• Green

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CCSS.HSS.ID.A.2

CCSS.HSS.ID.A.3

Parvati's potions quiz grade had a z-score of 1.8, Lavender's score on her divination quiz had a z-score of 0.7. Who did better?

• Parvati, she was 1.8 points above the mean and Lavender was only above by 0.7 points. 
• Parvati, she was 1.8 standard deviations above the mean and Lavender was only above by 0.7 standard deviations. 
• You can't tell if you don't know which class Hermione is in. 
• You can't tell if the scores were on different quizzes. 

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CCSS.HSS.ID.A.2