The CPI for 1930 was 16.7, while for 1939 it was 13.9. If an item costs $100 in 1930, how much would it have cost in 1939?

Step-by-step explanation:

If the CPI for 1930 was 16.7, while for 1939 it was 13.9, the change in CPI will be 16.7 - 13.9 = 2.8. The amount lost within the year 19.30 to 1939 if the cost of the item in 1930 is $100 will be expressed as;

= 2.8/16.7 * 100

= 280/16.7

= $16.8

The amount the item would have cost in 1939 will be $100 - $16.8 = $83.2

step-by-step explanation:

check above link.

graphically?   well, you graph them both, the solutions is where they both intersect each other, since there are two solutions, meaning they will meet twice, or namely the linear will run into the quadratic curve twice, and where they meet, those x,y coordinates are the solutions to the system.