Finding the Fourth Proportional to 1,139.12, 1,708.72 and 522.86

Step by Step Solution

1. Step 1: Write the proportion equation
   1,139.12 : 1,708.72 = 522.86 : x
2. Step 2: Convert to fraction form
   1,139.12/1,708.72 = 522.86/x
3. Step 3: Cross multiply
   1,139.12x = 1,708.72 × 522.86
4. Step 4: Simplify right side
   1,139.12x = 893,421.34
5. Step 5: Solve for x
   x = 893,421.34/1,139.12
6. Step 6: Final answer
   x = 784.31