Finding the Fourth Proportional to 1,103.93, 1,655.69 and 642.61

Step by Step Solution

1. Step 1: Write the proportion equation
   1,103.93 : 1,655.69 = 642.61 : x
2. Step 2: Convert to fraction form
   1,103.93/1,655.69 = 642.61/x
3. Step 3: Cross multiply
   1,103.93x = 1,655.69 × 642.61
4. Step 4: Simplify right side
   1,103.93x = 1,063,957.21
5. Step 5: Solve for x
   x = 1,063,957.21/1,103.93
6. Step 6: Final answer
   x = 963.79