Finding the Fourth Proportional to 31,508.66, 47,267.31 and 13,978.10

Step by Step Solution

1. Step 1: Write the proportion equation
   31,508.66 : 47,267.31 = 13,978.10 : x
2. Step 2: Convert to fraction form
   31,508.66/47,267.31 = 13,978.10/x
3. Step 3: Cross multiply
   31,508.66x = 47,267.31 × 13,978.10
4. Step 4: Simplify right side
   31,508.66x = 660,707,185.91
5. Step 5: Solve for x
   x = 660,707,185.91/31,508.66
6. Step 6: Final answer
   x = 20,969.07