Finding the Fourth Proportional to 59,789.28, 81,911.67 and 57,547.20

Step by Step Solution

1. Step 1: Write the proportion equation
   59,789.28 : 81,911.67 = 57,547.20 : x
2. Step 2: Convert to fraction form
   59,789.28/81,911.67 = 57,547.20/x
3. Step 3: Cross multiply
   59,789.28x = 81,911.67 × 57,547.20
4. Step 4: Simplify right side
   59,789.28x = 4,713,787,255.82
5. Step 5: Solve for x
   x = 4,713,787,255.82/59,789.28
6. Step 6: Final answer
   x = 78,840.01