Standard Variation

Is this the graph of a direct variation?

• Yes

• No

Is the given table a direct variation? If so, what is the constant?

• Yes; 1/4

• Yes; 4

• Yes; 2

• No

Does the relationship represent direct variation?

• Yes

• No

Data on the weights of various dog breeds is shown. Which of the following BEST describes what would happen to the standard deviation if the average weight of a St. Bernard, which weighs around 160 pounds, was added to the list?

• The Standard Deviation will increase.

• The Standard Deviation will decrease.

• The Standard Deviation will be unchanged.

• The Standard Deviation will be impossible to calculate.

Answer explanation

Remember, the standard deviation describes how spread out the numbers are. If a data value is added to the data set that widens the range of the data, it will always increase the standard deviation.

This is true even if a value that is LOWER than all the data is added. The standard deviation will still increase, because the range of the data is widened.

Which curve has the greater standard deviation?

• Red

• Black

• Blue

Does the following represents direct variation?

• Yes

• No

Which of the given graphs is a direct variation?

• A

• B

• C

• D

Does the following represents direct variation?

• Yes

• No

Is this a direct variation?

• yes

• no

Write the equation for the table given.

• y = 1/3x

• y = 3x

• y = 1/2x