Below we load the obama_vs_mccain dataset:

 

                  State Region Obama McCain Turnout Unemployment Income Population ...
1               Alabama     IV 38.74  60.32    61.6          5.9  22732    4802982
2                Alaska      X 37.89  59.42    68.0          6.6  29382     721523
3               Arizona     IX 44.91  53.39    55.7          7.1  25203    6412700
4              Arkansas     VI 38.86  58.72    53.1          5.8  20977    2926229
5            California     IX 60.94  36.91    62.0          8.2  29020   37341989
6              Colorado   VIII 53.66  44.71    70.8          5.4  29679    5044930
7           Connecticut      I 60.59  38.22      NA          6.2  36468    3581628
8  District of Columbia    III 92.46   6.53    62.0          7.4  40846     601723
9              Delaware    III 61.91  36.93    66.7          5.9  28935     900877
10              Florida     IV 50.91  48.10    67.4          7.3  26503   18900773
...

 

Find the (Pearson) correlation between the percentage of unemployed people within the states and the percentage of people who voted for Obama (no need to store it in an object).

(from: Cotton, 2013, Learning R, O’Reilly)