12.13 = 12 13/100....the numbers to the left of the decimal are ur numbers greater then 1....the numbers to the right of the decimal are ur numbers less then 1, ur fractions. Notice the last number (3), it is in the hundredths place...so put it over 100...and then the whole number...giving u 12 13/100
The price would go down as people would be more willing to buy cheaper potatoes and the producers would want to sell them for a lower price to get rid of them easy and fast.