Finding the Fourth Proportional to 143,478.12, 215,329.50 and 99,414.12

Step by Step Solution

1. Step 1: Write the proportion equation
   143,478.12 : 215,329.50 = 99,414.12 : x
2. Step 2: Convert to fraction form
   143,478.12/215,329.50 = 99,414.12/x
3. Step 3: Cross multiply
   143,478.12x = 215,329.50 × 99,414.12
4. Step 4: Simplify right side
   143,478.12x = 21,406,792,752.54
5. Step 5: Solve for x
   x = 21,406,792,752.54/143,478.12
6. Step 6: Final answer
   x = 149,199.01