Finding the Fourth Proportional to 1,162.12, 1,603.71 and 638.15

Step by Step Solution

1. Step 1: Write the proportion equation
   1,162.12 : 1,603.71 = 638.15 : x
2. Step 2: Convert to fraction form
   1,162.12/1,603.71 = 638.15/x
3. Step 3: Cross multiply
   1,162.12x = 1,603.71 × 638.15
4. Step 4: Simplify right side
   1,162.12x = 1,023,407.54
5. Step 5: Solve for x
   x = 1,023,407.54/1,162.12
6. Step 6: Final answer
   x = 880.64