Question

Part 1

For a set of two-variable data, the correlation r can be used to assess:

Group of answer choices

both the direction and the stength.

the strength only.

the direction only.

the form/shape only.

Part 2

The correlation r has:

Group of answer choices

the same units as the response variable y.

no units.

the same units as x times y.

the same units as the explanatory variable x.

Part 3

The correlation between two variables will be closer to zero if:

Group of answer choices

there is more variation in the response variable.

there is more variation in either of the variables.

there is more variation in the explanatory variable.

the data points very closely follow along a line.

Part 4

Which of the following statements is TRUE?

Group of answer choices

Correlation is not affected by the scale of the data (e.g., meters versus yards, or Celsius versus Fahrenheit).

All of these statements are true.

Calculation of correlation is based on standardizing both the x and y variables.

When computing correlation, it does not matter which of the variables is called x and which is called y.

Part 5

A scatterplot exhibits a positive association. Any outliers observed in the plot will:

Group of answer choices

decrease the correlation.

not impact the correlation.

impact the correlation in an unpredictable way.

increase the correlation.

Part 6

the correlation between Pulse Rate and Time to Swim 2000 Yards is r=-0.75. What percent of the variation in these swimmers' pulse rates is explained by the variation in their swimming times?

Group of answer choices

75%

56%

25%

87%

Answer 1

1.

Both the direction and strength.

2.

The correlation r has no unit.

It is unit less quantity.

3.

There is more variation in either of the variables.

4.

Correlation is not affected by the scale of the data (e.g., meters versus yards, or Celsius versus Fahrenheit). -True

Calculation of correlation is based on standardizing both the x and y variables. -False

When computing correlation, it does not matter which of the variables is called x and which is called y. - True

5.

impact the correlation in an unpredictable way.

6.

r2 = (-0.75)2 = 0.5625

56%