The price of gas was $1.80 in September then $2.07 in October. Find the percent of change from

September to October.

The percent increase from $1.80 to $2.07 is 15%.

2.07 / 1.80 = 1.15 - 1 = 15% increase.

If you were trying to find how much $1.80 of $2.07 was in percentage, then here you go:

1.80 * 100 (out of 100%) = 180

180 / 2.07 = 86.95

86.95%