Correlation Scenario

Name the type of association for the scenario below:

Pounds of cherries you buy and amount of money you spend on cherries

• Positive

• Negative

• No Association

Name the type of association for the scenario below:

Speed of a train and the amount of time it takes for the train to get to its destination

• Positive

• Negative

• No Association

In a positive association, as the x-value increases the y-value (a)   .

Tags

CCSS.HSF-LE.A.1B

If there is a negative association, as the x-value increases, the y-value (a)   .

Provide a real-life example of two variables that have a positive association.

Tags

CCSS.HSF-LE.A.1B

Draw a graph to represent the likely correlation between school absences and grades.

A negative correlation is represented by two variables where one (a)   while the other variable increases.

Thirteen young adults kept track of how many hours they worked at a restaurant and how many texts they sent during their shift. The equation of the line of best fit is: y = 9.15x + 66.23. The correlation coefficient for the data is r = -0.859. Which statements about the scenario are true?

• The value of the correlation coefficient is very close to -1, so there is no association between the number of hours worked and the number of texts sent.

• The line of best fit indicates, in general, the number of texts sent, on average, about 9 less for every hour that is worked.

• If the linear trend holds, the number of texts sent would be 0 for someone who has worked 8,274 hours in a shift.

• The number of texts sent during a shift tends to decrease as the number of hours increases.

Tags

CCSS.HSF.LE.B.5

Which of the following statements indicates a weak negative correlation?

• It is reasonable to assume a correlation coefficient is around -0.3 for the scenario.

• The slope of the line of best fit for the scenario will be close to 1.

• The correlation coefficient will be closer to -1 than it is to 0.

• The slope of the line of best fit for the related scatterplot will be negative.

Of the correlation coefficients below, which is most likely describing two variables that have no relationship?

• r = -0.95

• r = 0.01

• r = 0.39

• r = -0.68