Finding the Fourth Proportional to 9,712.78, 14,567.58 and 3,139

Step by Step Solution

1. Step 1: Write the proportion equation
   9,712.78 : 14,567.58 = 3,139 : x
2. Step 2: Convert to fraction form
   9,712.78/14,567.58 = 3,139/x
3. Step 3: Cross multiply
   9,712.78x = 14,567.58 × 3,139
4. Step 4: Simplify right side
   9,712.78x = 45,727,633.62
5. Step 5: Solve for x
   x = 45,727,633.62/9,712.78
6. Step 6: Final answer
   x = 4,707.99