Finding the Fourth Proportional to 1,387.92, 2,081.86 and 522.42

Step by Step Solution

1. Step 1: Write the proportion equation
   1,387.92 : 2,081.86 = 522.42 : x
2. Step 2: Convert to fraction form
   1,387.92/2,081.86 = 522.42/x
3. Step 3: Cross multiply
   1,387.92x = 2,081.86 × 522.42
4. Step 4: Simplify right side
   1,387.92x = 1,087,605.30
5. Step 5: Solve for x
   x = 1,087,605.30/1,387.92
6. Step 6: Final answer
   x = 783.62