Finding the Fourth Proportional to 81,978.62, 122,980.86 and 28,685.48

Step by Step Solution

1. Step 1: Write the proportion equation
   81,978.62 : 122,980.86 = 28,685.48 : x
2. Step 2: Convert to fraction form
   81,978.62/122,980.86 = 28,685.48/x
3. Step 3: Cross multiply
   81,978.62x = 122,980.86 × 28,685.48
4. Step 4: Simplify right side
   81,978.62x = 3,527,764,999.91
5. Step 5: Solve for x
   x = 3,527,764,999.91/81,978.62
6. Step 6: Final answer
   x = 43,032.74