Finding the Fourth Proportional to 1,086.38, 1,499.20 and 620.63

Step by Step Solution

1. Step 1: Write the proportion equation
   1,086.38 : 1,499.20 = 620.63 : x
2. Step 2: Convert to fraction form
   1,086.38/1,499.20 = 620.63/x
3. Step 3: Cross multiply
   1,086.38x = 1,499.20 × 620.63
4. Step 4: Simplify right side
   1,086.38x = 930,448.50
5. Step 5: Solve for x
   x = 930,448.50/1,086.38
6. Step 6: Final answer
   x = 856.47