Answer:
Scale factor = 2
Step-by-step explanation:
Scale factors deal multiplication. So, you would need to find a number to multiply by 6 to get 12. You can do this by doing 12 / 6.
12 / 6 = 2
The formula required to answer this is:

where A is the amount of the principal P after n compounding periods per year at r interest rate (as a decimal fraction).
Plugging in the given values, we get:

Rounding to the nearest dollar, we get $662.00. Therefore a is the best answer choice.
Market 1: 3,90/10 = 0.390 $
market 2: 4,44/12= 0,37 $
best price in market 2