Help with this question. When i do the work I end up with 12.85 which is incorrect and i dont know what i am doing wrong.

For the scores 4,6,9,10,13,15,17,19,20, and 22, calculate the 45th percentile using the formula: R=p/100*(n+1) to compute the rank first, then the percentile (Method 3, in Lane Text).

A.) 15.50

B 16.30

C 17.10

D 17.30

E 17.50

When I do the work I did R=45/100(10+1) = 9/20(10+1)= 9/20(11) = 99/20 or 4.95 the IR = 4 FR = 0.95 so,

(0.95)(13-10)+10

(0.95)(3)+10

2.85+10 = 12.85 ...........i did something wrong please help me.