Linear Regressions and Scatterplots

Find the equation of the line of best fit for the given data

• y = 163.41x+1.49

• y =- 163.41x+ 4.19

• y =- 4.19x+163.41

• y = 4.19x -163.41

If Joe worked 30 hours, how much is he expected to earn?

• $600

• $200

• $1000

• $800

Which scatter plot diagram shows the strongest positive correlation?

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Which graph represents data that has a correlation coefficient close to -1?

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The correlation coefficient, r is used to determine

• y values given values of x.

• x values given values of y.

• the strength and direction of relationship between x and y.

• none of these.

Describe the relationship between the variables.

• Strong positive correlation

• Weak positive correlation

• Strong negative correlation

• Weak negative correlation

Describe the relationship.

• Strong positive correlation

• Strong negative correlation

• Weak positive correlation

• No correlation

Estimate the correlation coefficient.

• r=0

• r=-1

• r=1

• r=2

Two variables have a positive association when

• the value of one variable tends to increase as the other variable increases.

• the value of one variable tends to increase as the other variable decreases.

• the value of one variable tends to increase regardless how the other variable change.

• the values of both variables are always positive.

Answer explanation

Both variables move in the same direction although the numbers are negative.

Coefficient of correlation lies between

• 0 and +1

• 0 and -1

• -1 and +1

• -5 and +5

Answer explanation

The value of r must be between -1 and +1