Finding the Fourth Proportional to 1,086.58, 1,499.79 and 620.92

Step by Step Solution

1. Step 1: Write the proportion equation
   1,086.58 : 1,499.79 = 620.92 : x
2. Step 2: Convert to fraction form
   1,086.58/1,499.79 = 620.92/x
3. Step 3: Cross multiply
   1,086.58x = 1,499.79 × 620.92
4. Step 4: Simplify right side
   1,086.58x = 931,249.61
5. Step 5: Solve for x
   x = 931,249.61/1,086.58
6. Step 6: Final answer
   x = 857.05