First, converting R percent to r a decimal
r = R/100 = 6%/100 = 0.06 per year,
putting time into years for simplicity,
4 months ÷ 12 months/year = 0.333333 years,
then, solving our equation
I = $ 376.00
I = 18800 × 0.06 × 0.333333 = 375.999624
I = $ 376.00
The simple interest accumulated
on a principal of $ 18,800.00
at a rate of 6% per year
for 0.333333 years (4 months) is $ 376.00.