Standard Deviation of Random Variables

• 1.67

• 1.0775

• 1.581

• 1.414

The mean hourly salary for a high school graduate is $13.50 per hour with a standard deviation of $5.75. The mean hourly salary for a person with an Associate's degree is $19.75 with a standard deviation of $9.25. What is the standard deviation of the difference in the hourly salaries between a high school graduate and a person who earned an Associate's degree?

• $10.89

• $7.25

• $-3.50

• $15.00

The graph shows the probability distribution for the number of orders per week for a randomly selected week at an Etsy store. What is the expected number of orders and the standard deviations of the number of orders?

• 44.5, 2.449

• 44.5, 2.291

• 44.64, 1.694

• 44.64, 1.672

The model shown above shows the probability for rental units based on the number of rooms. What is the expected value and the standard deviation of the number of rooms in a rental unit?

• 5, 2.7386

• 5, 2.5820

• 4.355, 1.5647

• 4.355, 1.2996

It is a number which describes the spread of the distribution.

Standard deviation describes what characteristic of a set of data?

• The number of data values.

• The expected data value.

• The spread of the data values from the mean.

• The range of the data values.

List each set of data by color from the lowest standard deviation to the highest standard deviation.

• blue, green, pink, red

• red, pink, green, blue

• pink, green, red, blue

• blue, green, red, pink

What does σ represent?

• sample standard deviation

• population/distribution standard deviation

• sample mean

• population/distribution mean

The mean weight of a dog is 34 pounds with a standard deviation of 6.7 pounds. The mean weight of a cat is 12 pounds with a standard deviation of 3.1 pounds. If you have 2 dogs and 1 cat, what is the mean and standard deviation of their total weight?

• 80, 9.969

• 80, 16.5

• 46, 7.382

• 46, 16.5