Original: 45

New: 50

Since the new amount is greater than the original, this is a percent of increase.

The amount of change = New Amount – Original Amount.

The amount of change = .

Let r be the percentage of increase.

Use the original number, 45 as the base.

The percent proportion is

To solve for r, first find the cross products.

                                       (Multiply: )

                                 (Divide each side by 45)

                                          (Cancel common terms)

                                        (Divide: )

The percentage of increase by 11.11%

The percent of change is a percent of increase.

The percentage of increase by 11.11%.