In: Statistics and Probability
1. Use the data below to find the linear regression equation that best represents the given data and predict the revenue in 2013 (Copy data to Excel)
2. Then create Two new columns that represent the predication y =mx+b for each year and percent of growth for each year = (Revenue/Predication)*100
3. Use Excel to graph the linear model (x-axis years, y-axis revenue) and the linear equation of best fit.
Year | Revenue | Predication | Percent of growth (%) |
2001 | 3665 | ||
2002 | 4163 | ||
2003 | 4750 | ||
2004 | 5287 | ||
2005 | 5825 | ||
2006 | 6395 | ||
2007 | 6834 | ||
2008 | 6994 | ||
2009 | 7401 | ||
2010 | 7867 | ||
2011 | 8548 | ||
2012 | 9331 |
Solution :-
Given data,
1) Process: data -> data analysis -> regression -> dependent variable = revenue ; independent variable = t
Output:
regression equation: revenue = 3282.438 + 482.958*t
for t = 13;
predicted revenue = =3282.438 + 482.958*13
= 9560.892
2)
Year | t | Revenue | Predication; yhat = 3282.438 + 482.958*t | Percent of growth (%) = (Revenue/Predication)*100 |
2001 | 1 | 3665 | 3765.397436 | 0.973336829 |
2002 | 2 | 4163 | 4248.355478 | 0.979908584 |
2003 | 3 | 4750 | 4731.31352 | 1.003949533 |
2004 | 4 | 5287 | 5214.271562 | 1.013947958 |
2005 | 5 | 5825 | 5697.229604 | 1.022426759 |
2006 | 6 | 6395 | 6180.187646 | 1.034758225 |
2007 | 7 | 6834 | 6663.145688 | 1.025641689 |
2008 | 8 | 6994 | 7146.10373 | 0.978715152 |
2009 | 9 | 7401 | 7629.061772 | 0.970106184 |
2010 | 10 | 7867 | 8112.019814 | 0.969795462 |
2011 | 11 | 8548 | 8594.977855 | 0.994534267 |
2012 | 12 | 9331 | 9077.935897 | 1.027876833 |
3)
4)
a) correlation coefficient = 0.995294997 [Excel
function used CORREL(t,revenue)]
b) regresion line: y = 482.96x - 962634 [from the
column of coefficients in regression output]
c) coefficient of determination, R^2 = r^2 = 0.995295^2 =
0.990612137
d) SE = 177.7907239 [ deom standard error in table
1]