Finding the Fourth Proportional to 105,087.20, 157,776.60 and 65,721.20

Step by Step Solution

1. Step 1: Write the proportion equation
   105,087.20 : 157,776.60 = 65,721.20 : x
2. Step 2: Convert to fraction form
   105,087.20/157,776.60 = 65,721.20/x
3. Step 3: Cross multiply
   105,087.20x = 157,776.60 × 65,721.20
4. Step 4: Simplify right side
   105,087.20x = 10,369,267,483.92
5. Step 5: Solve for x
   x = 10,369,267,483.92/105,087.20
6. Step 6: Final answer
   x = 98,672.98