Finding the Fourth Proportional to 105,684.47, 145,859.58 and 65,411.21

Step by Step Solution

1. Step 1: Write the proportion equation
   105,684.47 : 145,859.58 = 65,411.21 : x
2. Step 2: Convert to fraction form
   105,684.47/145,859.58 = 65,411.21/x
3. Step 3: Cross multiply
   105,684.47x = 145,859.58 × 65,411.21
4. Step 4: Simplify right side
   105,684.47x = 9,540,851,617.89
5. Step 5: Solve for x
   x = 9,540,851,617.89/105,684.47
6. Step 6: Final answer
   x = 90,276.76