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The scatterplot and regression line below show the relationship between the percentage of American adults who smoke and years since 1945. The fitted line has a y-intercept of 41.

a) Find the slope of the regression line.
b) Determine the equation of the regression line.
c) Calculate the correlation coefficient.
d) None of the above.

User Realnot
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1 Answer

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Final answer:

The assignment involves finding the slope and equation of a regression line and calculating the correlation coefficient to determine the strength of the linear relationship between two variables. Specific calculations cannot be provided without the actual data or scatterplot.

Step-by-step explanation:

The question pertains to the calculation and interpretation of a linear regression line based on a given scatterplot. To address the various parts of the question:

a. The slope of the regression line can be found using the rise-over-run method from the scatterplot or by calculating the change in the dependent variable over the change in the independent variable using the least-squares formula.

b. Once the slope is determined, the equation of the regression line can be written in the form ŷ = a + bx, where a is the y-intercept given as 41, and b is the slope.

c. The correlation coefficient, typically denoted as r, measures the strength and direction of the linear relationship between two variables. Its significance can often be determined by a statistical test such as a t-test.

Without the actual scatterplot and numerical data, we cannot compute the exact slope, equation of the regression line, or correlation coefficient; we can only describe the methods to find them.

User GreenTurtle
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