Finding the Fourth Proportional to 80,721.72, 121,051.86 and 36,915

Step by Step Solution

1. Step 1: Write the proportion equation
   80,721.72 : 121,051.86 = 36,915 : x
2. Step 2: Convert to fraction form
   80,721.72/121,051.86 = 36,915/x
3. Step 3: Cross multiply
   80,721.72x = 121,051.86 × 36,915
4. Step 4: Simplify right side
   80,721.72x = 4,468,629,411.90
5. Step 5: Solve for x
   x = 4,468,629,411.90/80,721.72
6. Step 6: Final answer
   x = 55,358.45