Finding the Fourth Proportional to 1,118.61, 1,677.72 and 425.10

Step by Step Solution

1. Step 1: Write the proportion equation
   1,118.61 : 1,677.72 = 425.10 : x
2. Step 2: Convert to fraction form
   1,118.61/1,677.72 = 425.10/x
3. Step 3: Cross multiply
   1,118.61x = 1,677.72 × 425.10
4. Step 4: Simplify right side
   1,118.61x = 713,198.77
5. Step 5: Solve for x
   x = 713,198.77/1,118.61
6. Step 6: Final answer
   x = 637.58