Finding the Fourth Proportional to 99,433.50, 137,218.50 and 54,721.50

Step by Step Solution

1. Step 1: Write the proportion equation
   99,433.50 : 137,218.50 = 54,721.50 : x
2. Step 2: Convert to fraction form
   99,433.50/137,218.50 = 54,721.50/x
3. Step 3: Cross multiply
   99,433.50x = 137,218.50 × 54,721.50
4. Step 4: Simplify right side
   99,433.50x = 7,508,802,147.75
5. Step 5: Solve for x
   x = 7,508,802,147.75/99,433.50
6. Step 6: Final answer
   x = 75,515.82