Finding the Fourth Proportional to 1,123.72, 1,686.12 and 539.00

Step by Step Solution

1. Step 1: Write the proportion equation
   1,123.72 : 1,686.12 = 539.00 : x
2. Step 2: Convert to fraction form
   1,123.72/1,686.12 = 539.00/x
3. Step 3: Cross multiply
   1,123.72x = 1,686.12 × 539.00
4. Step 4: Simplify right side
   1,123.72x = 908,824.04
5. Step 5: Solve for x
   x = 908,824.04/1,123.72
6. Step 6: Final answer
   x = 808.76