Finding the Fourth Proportional to 8,782.29, 12,113.69 and 5,421.87

Step by Step Solution

1. Step 1: Write the proportion equation
   8,782.29 : 12,113.69 = 5,421.87 : x
2. Step 2: Convert to fraction form
   8,782.29/12,113.69 = 5,421.87/x
3. Step 3: Cross multiply
   8,782.29x = 12,113.69 × 5,421.87
4. Step 4: Simplify right side
   8,782.29x = 65,678,825.29
5. Step 5: Solve for x
   x = 65,678,825.29/8,782.29
6. Step 6: Final answer
   x = 7,478.55