Question 1

## 
## Call:
## lm(formula = registered ~ temp + I(temp * temp) + I(temp * temp * 
##     temp) + season + Promotion + mnth + workingday + weathersit, 
##     data = bikeshare)
## 
## Coefficients:
##           (Intercept)                   temp         I(temp * temp)  
##              985.1253              -190.0400                20.1688  
## I(temp * temp * temp)                season2                season3  
##               -0.4296               613.2094              1023.0692  
##               season4             Promotion1                  mnth2  
##             1606.3497              1743.4083               117.2687  
##                 mnth3                  mnth4                  mnth5  
##              127.3456               -75.5088               182.6047  
##                 mnth6                  mnth7                  mnth8  
##              423.6630               292.0030               147.0608  
##                 mnth9                 mnth10                 mnth11  
##              166.2658              -261.3192              -488.0237  
##                mnth12             workingday            weathersit2  
##             -190.1047               969.3214              -544.4747  
##           weathersit3  
##            -2063.0787
## 
## Call:
## lm(formula = registered ~ temp + I(temp * temp) + I(temp * temp * 
##     temp) + season + Promotion + mnth + workingday + weathersit, 
##     data = bikeshare)
## 
## Residuals:
##     Min      1Q  Median      3Q     Max 
## -3573.3  -273.3    76.2   354.4  1570.7 
## 
## Coefficients:
##                         Estimate Std. Error t value Pr(>|t|)    
## (Intercept)             985.1254   353.8938   2.784  0.00552 ** 
## temp                   -190.0400    66.1523  -2.873  0.00419 ** 
## I(temp * temp)           20.1688     3.5821   5.630 2.59e-08 ***
## I(temp * temp * temp)    -0.4296     0.0598  -7.183 1.73e-12 ***
## season2                 613.2094   136.1234   4.505 7.77e-06 ***
## season3                1023.0692   162.6551   6.290 5.56e-10 ***
## season4                1606.3497   136.4228  11.775  < 2e-16 ***
## Promotion1             1743.4083    43.8597  39.750  < 2e-16 ***
## mnth2                   117.2686   113.2083   1.036  0.30062    
## mnth3                   127.3456   131.1638   0.971  0.33193    
## mnth4                   -75.5088   190.5959  -0.396  0.69210    
## mnth5                   182.6047   204.3843   0.893  0.37193    
## mnth6                   423.6630   210.3860   2.014  0.04441 *  
## mnth7                   292.0030   235.9319   1.238  0.21625    
## mnth8                   147.0608   228.0975   0.645  0.51931    
## mnth9                   166.2659   205.7132   0.808  0.41922    
## mnth10                 -261.3192   188.1379  -1.389  0.16528    
## mnth11                 -488.0237   180.8023  -2.699  0.00712 ** 
## mnth12                 -190.1047   143.7876  -1.322  0.18655    
## workingday              969.3214    46.8691  20.681  < 2e-16 ***
## weathersit2            -544.4747    47.2741 -11.517  < 2e-16 ***
## weathersit3           -2063.0787   132.9827 -15.514  < 2e-16 ***
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 584.3 on 709 degrees of freedom
## Multiple R-squared:  0.8638, Adjusted R-squared:  0.8598 
## F-statistic: 214.1 on 21 and 709 DF,  p-value: < 2.2e-16

Question 2

It does not look like there are problems multicollinearity at this time. It appears as though the correlations between variables in this model are low (none outside of -.3 to .3). As for linearity, there may be some issues but the model seems to fit well. The biggest worry for me in terms of linearity was the temperature variable, but setting it to cubic has made me more comfortable with the model.

Question 3

June (mnth 6) appears to have the most riders. If it were to become unseasonably cold and rainy, this would drop the number of riders by about 544, however it would not change the coefficient for month.

Question 4

The coefficient for promotion is 1743, meaning there is an average of 1743 additional riders when there is a promotion. This leads me to the initial judgement that the marketing department is correct to an extent, given the fact that Promotions seem to have nearly the biggest impact on number of riders (right behind a bad weather situation).

Question 5

## 
## Call:
## lm(formula = casual ~ temp + I(temp * temp) + I(temp * temp * 
##     temp) + season + Promotion + mnth + workingday + weathersit, 
##     data = bikeshare)
## 
## Coefficients:
##           (Intercept)                   temp         I(temp * temp)  
##              990.2946              -130.2807                11.2885  
## I(temp * temp * temp)                season2                season3  
##               -0.2195               190.0101               162.0304  
##               season4             Promotion1                  mnth2  
##              106.6839               297.9581                 7.7147  
##                 mnth3                  mnth4                  mnth5  
##              263.8073               209.7846               203.5973  
##                 mnth6                  mnth7                  mnth8  
##              196.0206               294.5666               170.2349  
##                 mnth9                 mnth10                 mnth11  
##              180.0471               249.6970               110.8257  
##                mnth12             workingday            weathersit2  
##               14.3201              -796.4908              -188.9696  
##           weathersit3  
##             -569.2973
## 
## Call:
## lm(formula = casual ~ temp + I(temp * temp) + I(temp * temp * 
##     temp) + season + Promotion + mnth + workingday + weathersit, 
##     data = bikeshare)
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -1292.54  -212.31   -33.07   183.60  1578.29 
## 
## Coefficients:
##                         Estimate Std. Error t value Pr(>|t|)    
## (Intercept)            990.29459  217.22571   4.559 6.06e-06 ***
## temp                  -130.28067   40.60532  -3.208  0.00139 ** 
## I(temp * temp)          11.28848    2.19876   5.134 3.67e-07 ***
## I(temp * temp * temp)   -0.21952    0.03671  -5.980 3.53e-09 ***
## season2                190.01015   83.55474   2.274  0.02326 *  
## season3                162.03040   99.84029   1.623  0.10506    
## season4                106.68394   83.73849   1.274  0.20308    
## Promotion1             297.95811   26.92179  11.068  < 2e-16 ***
## mnth2                    7.71469   69.48908   0.111  0.91163    
## mnth3                  263.80726   80.51047   3.277  0.00110 ** 
## mnth4                  209.78459  116.99079   1.793  0.07337 .  
## mnth5                  203.59729  125.45433   1.623  0.10506    
## mnth6                  196.02056  129.13829   1.518  0.12948    
## mnth7                  294.56663  144.81880   2.034  0.04232 *  
## mnth8                  170.23493  140.00991   1.216  0.22444    
## mnth9                  180.04715  126.27007   1.426  0.15434    
## mnth10                 249.69704  115.48204   2.162  0.03094 *  
## mnth11                 110.82567  110.97935   0.999  0.31832    
## mnth12                  14.32013   88.25911   0.162  0.87115    
## workingday            -796.49078   28.76899 -27.686  < 2e-16 ***
## weathersit2           -188.96961   29.01760  -6.512 1.40e-10 ***
## weathersit3           -569.29732   81.62694  -6.974 7.05e-12 ***
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 358.7 on 709 degrees of freedom
## Multiple R-squared:  0.735,  Adjusted R-squared:  0.7272 
## F-statistic: 93.64 on 21 and 709 DF,  p-value: < 2.2e-16

It appears the promotion impacts casual drivers as well, but much less. An average of 297 more casual bikers were riding when there is a promotion, vs.ย an additional 1743 for registered riders. Though far less, causal riders are still influenced significantly by the promotion compared to other variables in the model. The Rsq value is a bit lower, indicating this model is less of a fit for casual riders.

Question 6

To make a more meaningful report, I need to know the financials information surrounding the bikeshare program. What are the exact business costs for the company? What does the profit margin look like? Without the actually monetary information, it is hard to clean exactly what the promotion is doing. With this information, it would be much more clear as to weather or not the promotion was a success both for registered and casual bikers.