In: Statistics and Probability
Data on advertising expenditures and revenue (in thousands of dollars) for the Four Seasons Restaurant follow. Advertising Expenditures Revenue 1 20 2 33 4 44 6 40 10 52 14 53 20 54
a. Let X equal advertising expenditures and Y equal revenue. Complete the estimated regression equation below (to 2 decimals). y =( )+( )x b. Compute the following (to 1 decimal). SSE ( ) SST ( ) SSR ( )MSR ( ) MSE ( )
c. Test whether revenue and advertising expenditures are related at a .05 level of significance. Compute the F test statistic ( to 2 decimals).
x | y | (x-xbar)^2 | (y-ybar)^2 | (x-xbar)*(y-ybar) | |
1 | 20 | 51.020408 | 496.65306 | 159.1836735 | |
2 | 33 | 37.734694 | 86.22449 | 57.04081633 | |
4 | 44 | 17.163265 | 2.9387755 | -7.102040816 | |
6 | 40 | 4.5918367 | 5.2244898 | 4.897959184 | |
10 | 52 | 3.4489796 | 94.367347 | 18.04081633 | |
14 | 53 | 34.306122 | 114.79592 | 62.75510204 | |
20 | 54 | 140.59184 | 137.22449 | 138.8979592 | |
sum | 57 | 296 | 288.85714 | 937.42857 | 433.7142857 |
mean | 8.142857143 | 42.28571429 | sxx | syy | sxy |
slope=b1=sxy/sxx | 1.50148368 | ||||
intercept=b0=ybar-(slope*xbar) | 30.05934718 | ||||
SST | SYY | 937.42857 | |||
SSR | sxy^2/sxx | 651.21492 | |||
SSE | syy-sxy^2/sxx | 286.21365 |
The Fitted model is
y=30.1+1.50(Expenditure)
Ansb:
SSE=286.22
SST=937.43
SSR=651.21
#MSR=SSR/1=651.21
#MSE=SSE/(n-2)=57.24273
ANOVA | |||||
df | SS | MS | F | ||
Regression | 1 | 651.2149216 | 651.2149 | 11.37638 | |
Residual | (n-2)=5 | 286.2136499 | 57.24273 | ||
Total | 6 | 937.4285714 |
Ansc:
F-statistics=MSR/MSE=11.38
F-critical=6.608----using FINV(0.05,1,5)
P-value=0.0074
#P-value<0.05 hence we reject the null hypothesis at 5% l.o.s
#we reject the H0. Hence claim is significant