Finding the Fourth Proportional to 99,729.27, 137,624.99 and 57,288.15

Step by Step Solution

1. Step 1: Write the proportion equation
   99,729.27 : 137,624.99 = 57,288.15 : x
2. Step 2: Convert to fraction form
   99,729.27/137,624.99 = 57,288.15/x
3. Step 3: Cross multiply
   99,729.27x = 137,624.99 × 57,288.15
4. Step 4: Simplify right side
   99,729.27x = 7,884,280,784.43
5. Step 5: Solve for x
   x = 7,884,280,784.43/99,729.27
6. Step 6: Final answer
   x = 79,056.84