Descriptive Statistics Review

75% of the observations are above _____

• 6

• 10

• 11

• 13

50% of the observations are below _____

• 6

• 10

• 11

• 13

The mean is 100 and the standard deviation is 10. What is X at z = -2.00?

• -20.0

• 90.0

• 110.0

• 80.0

What is the probably of randomly choosing an item between these two z-values?

• 50% - (probability)

• (big probability) + (little probability)

• (big probability) - (little probability)

• 50% + (probability)

The mean is 100 and the standard deviation is 10. What is z at X = 130?

• 1.30

• 2.60

• -2.60

• 3.00

What is the probability to the left of the mean in a normal distribution?

• 100%

• 68%

• 50%

• 99.7%

We are trying to find the average price paid per pound. Which variables are X?

• Price

• Quantity

• Price * Quantity

• Price / Quantity

What is the probability of randomly choosing an item greater than this z-value?

• 50% + probability

• (big probability) - (little probability)

• (big probability) + (little probability)

• 50% - probability

What is the probably of randomly choosing an item less than this z-value?

• 50% - (probability)

• (big probability) + (little probability)

• (big probability) - (little probability)

• 50% + (probability)

The number of pages that Carolyn wrote in her journal each day from Monday to Friday is shown below:

9, 8, 12, 6, 10

What is the mean number of pages she wrote per day?

• 5

• 6

• 9

• 11