Answer:
17
Step-by-step explanation:
We have the following equation for compounding annual interest
AV=PV(1+i)ⁿ
We have
19200=7400(1+.06)ⁿ
Solve for n
divide both sides by 7400
2.594=(1.06)ⁿ
then use the following rule for exponents

which means that

Solve and get
16.362
which rounds to 17
Make the same denominator (12) and then make them both non mixed numbers 93/12 and 54.6666.../12
so 147.666.../12
12.305/12