Finding the Fourth Proportional to 99,685.50, 149,336.37 and 78,513.54

Step by Step Solution

1. Step 1: Write the proportion equation
   99,685.50 : 149,336.37 = 78,513.54 : x
2. Step 2: Convert to fraction form
   99,685.50/149,336.37 = 78,513.54/x
3. Step 3: Cross multiply
   99,685.50x = 149,336.37 × 78,513.54
4. Step 4: Simplify right side
   99,685.50x = 11,724,927,059.45
5. Step 5: Solve for x
   x = 11,724,927,059.45/99,685.50
6. Step 6: Final answer
   x = 117,619.18