To calculate the salary in the fourth year, we need to find the salary for each year:
Year 1: $45,000
Year 2: $45,000 x 1.07 = $48,150
Year 3: $48,150 x 1.07 = $51,581.50
Year 4: $51,581.50 x 1.07 = $55,304.10
Therefore, the expected salary in the fourth year is $55,304.10 rounded to the nearest dollar, which is $55,304.