Finding the Fourth Proportional to 1,087.18, 1,500.15 and 621.34

Step by Step Solution

1. Step 1: Write the proportion equation
   1,087.18 : 1,500.15 = 621.34 : x
2. Step 2: Convert to fraction form
   1,087.18/1,500.15 = 621.34/x
3. Step 3: Cross multiply
   1,087.18x = 1,500.15 × 621.34
4. Step 4: Simplify right side
   1,087.18x = 932,103.20
5. Step 5: Solve for x
   x = 932,103.20/1,087.18
6. Step 6: Final answer
   x = 857.36