Question

The table shows the sales of a health and beauty supply company, in millions of dollars, for several years. Let x be the number of years since 2010.
Year 2011 2012 2013 2014 2015
Sales 12.2 19.1 29.4 37.3 45.7


a. Write the equation for the best-fit line for the data. Round to the nearest hundredth, if necessary.



y =
x +

Part B
Select the correct choices to complete the sentence.
b. Find and interpret the correlation coefficient.



r ≈ , 1 of 4.
Select Choice



The equation , 2 of 4.
Select Choice
the data very well. Its , 3 of 4.
Select Choice
value means that as the years since 2010 increase, sales, in millions of dollars, , 4 of 4.
Select Choice
.

Answer 1

a. The equation for the line of best-fit is:

y = 8.52x + 11.7.

b. The correlation coefficient is of: 0.9987, hence there is a strong positive correlation between the variables.

How to find the equation of the line of best fit and the correlation coefficient?

To obtain the regression equation, also called line of best fit or least squares regression equation, we need to insert the points (x,y) in the calculator. These points are given on a table or in a scatter plot in the problem.

The points in this problem are given on the table as follows:

(0, 12.2), (1, 19.1), (2, 29.4), (3, 37.3), (4, 45.7).

As we consider the input x as the number of years since 2011.

Then, using the calculator, the equation is given as follows:

y = 8.52x + 11.7.

Using a correlation coefficient calculator, the numeric value of the coefficient is of:

r = 0.9987.

Hence the correlation between the variables is classified as follows:

• Positive, as the correlation coefficient is positive.

• Strong, as the correlation coefficient is greater than 0.6.

More can be learned about regression equations at brainly.com/question/26755306

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