Finding the Fourth Proportional to 8,700.78, 12,017.04 and 5,729.89

Step by Step Solution

1. Step 1: Write the proportion equation
   8,700.78 : 12,017.04 = 5,729.89 : x
2. Step 2: Convert to fraction form
   8,700.78/12,017.04 = 5,729.89/x
3. Step 3: Cross multiply
   8,700.78x = 12,017.04 × 5,729.89
4. Step 4: Simplify right side
   8,700.78x = 68,856,317.33
5. Step 5: Solve for x
   x = 68,856,317.33/8,700.78
6. Step 6: Final answer
   x = 7,913.81