For your role-playing game, each of your adventurer’s character attributes is calculated as the sum of the scores from three six-sided dice rolls. To save arm-ache, you decide to use R to generate the scores. Below is a helper function three_6d() to generate them.

Big scores give character bonuses and small scores give character penalties according to the following table:

Score	Bonus
3	-3
4, 5	-2
6 to 8	-1
9 to 12	0
13 to 15	+1
16, 17	+2
18	+3

Use the three_d6() function (below) to generate 1000 attribute scores. You should store these in an object called scores. Next, calculate the frequency of each bonus level in scores. You should store these frequencies in an object called freqs. Hint: before creating freqs you should divide the scores vector into groups according to the table above.

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