Test Stats Unit Math III

Given a mean of 75 and a standard deviation of 7, what percentage of scores are between 75 and 82?

• 68%

• 81.5%

• 16%

• 34%

Given a mean of 75 and a standard deviation of 7, what percentage of scores are between 61 and 89?

• 34%

• 99.7%

• 95%

• 2.5%

Given a mean of 75 and a standard deviation of 7, how many students out of 500 would score between 61 and 89?

• 475

• 400

• 340

• 80

Given a mean of 75 and a standard deviation of 7, how many students out of 500 would score between 75 and 82?

• 475

• 170

• 340

• 237

Given a mean of 75 and a standard deviation of 7, how many students out of 500 would score higher than 89?

• 11

• 12

• 36

• 237

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.

What shape is a normal distribution curve?

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

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.

By the way, what is standard deviation?

• good question

• how standardly something deviates

• average distance that data points are from the mean

• Idk but I should probably find out pretty soon

Brian scored an 78 on a Chemistry Exam. The average on the exam was a 68, with a standard deviation of 5. What is Brian's z-score?

• 2

• -2

• 1

• -1