Finding the Fourth Proportional to 90,615.43, 135,848.31 and 39,978.37

Step by Step Solution

1. Step 1: Write the proportion equation
   90,615.43 : 135,848.31 = 39,978.37 : x
2. Step 2: Convert to fraction form
   90,615.43/135,848.31 = 39,978.37/x
3. Step 3: Cross multiply
   90,615.43x = 135,848.31 × 39,978.37
4. Step 4: Simplify right side
   90,615.43x = 5,430,994,001.05
5. Step 5: Solve for x
   x = 5,430,994,001.05/90,615.43
6. Step 6: Final answer
   x = 59,934.54