Question

1.   The following table represents the internet advertising revenue (in billions).

     (x represents the time in years since 2007) Round function values to nearest hundredth.

Year 2007 2008 2009 2010 2011 2012 2013 2014

Internet Advertising Revenue (in billions) 21.2 23.4 22.7 25.8 28.5 32.6 36 40.5

a) Create a table of the r squared values together with each of your best fit curves (round to nearest thousandth).

b) Copy the best of the best fit functions here. Explain how you picked this function.

c) Use your best function to estimate the Internet Advertising Revenue this year.

Answer 1

This is the regression output from excel in tabular form

enter your data ---> go to Data Analysis Tab ---> select regression--->select your independent and dependent variables---->tick the box of labels---> select your output range that's it you will get the above output.

R-squared value is the square of the Multiple R value which is also called correlation coefficient. Below I am providing calculation for correlation if you want to know the procedure as excel just produce results directly.

Here X is year and Y is revenue.

sp r=0.9696 is correlation (multiple R) .

Now you can see another table where you can see coefficients for intercept and year how to calculate those? again I am providing you calculations below-

You can see the intercept coefficient -5788.07 matches with our calculation and also the slope coefficient of 2.744 matches with our calculation so that's how you can get these manually.

B) Your best fit function is y= -5488.07+2.744.x as you can also see above (this is also known as best fit regression equation). Explanation how we picked this?

the following equation is estimated by the method of least squares which ensures that the estimates we get for intercept and slope are best.

C) Revenue this year(2020) = -5488.07+ 2.744*2020 = 54.81 (just put 2020 in place of x)

I hope this helps you.

Thanks