Answer: 13%
Step-by-step explanation:
The formula to find the simple interest is given by :-
, where P is the principal amount, r is rate of interest () in decimal and t is the time ( in years).
Given : P = $19,100 , I=$9932.00 and t= 4 years
Substitute all the above values in the formula , we get

In percent , 
Hence, the rate of interest = 13%
4. 15 tens, 1 hundred, 5 tens
150
5. 18 tens, 1 hundred, 8 tens
180
note: I hope this helps. I haven't done this in a long time. Sorry X(