Finding the Fourth Proportional to 783.72, 1,081.89 and 686.52

Step by Step Solution

1. Step 1: Write the proportion equation
   783.72 : 1,081.89 = 686.52 : x
2. Step 2: Convert to fraction form
   783.72/1,081.89 = 686.52/x
3. Step 3: Cross multiply
   783.72x = 1,081.89 × 686.52
4. Step 4: Simplify right side
   783.72x = 742,739.12
5. Step 5: Solve for x
   x = 742,739.12/783.72
6. Step 6: Final answer
   x = 947.71