Finding the Fourth Proportional to 65,978.28, 91,046.16 and 39,123.36

Step by Step Solution

1. Step 1: Write the proportion equation
   65,978.28 : 91,046.16 = 39,123.36 : x
2. Step 2: Convert to fraction form
   65,978.28/91,046.16 = 39,123.36/x
3. Step 3: Cross multiply
   65,978.28x = 91,046.16 × 39,123.36
4. Step 4: Simplify right side
   65,978.28x = 3,562,031,694.30
5. Step 5: Solve for x
   x = 3,562,031,694.30/65,978.28
6. Step 6: Final answer
   x = 53,987.94