Finding the Fourth Proportional to 1,086.74, 1,499.14 and 687.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,086.74 : 1,499.14 = 687.72 : x
2. Step 2: Convert to fraction form
   1,086.74/1,499.14 = 687.72/x
3. Step 3: Cross multiply
   1,086.74x = 1,499.14 × 687.72
4. Step 4: Simplify right side
   1,086.74x = 1,030,992.31
5. Step 5: Solve for x
   x = 1,030,992.31/1,086.74
6. Step 6: Final answer
   x = 948.71