Finding the Fourth Proportional to 10,931.60, 15,085.72 and 6,215.88

Step by Step Solution

1. Step 1: Write the proportion equation
   10,931.60 : 15,085.72 = 6,215.88 : x
2. Step 2: Convert to fraction form
   10,931.60/15,085.72 = 6,215.88/x
3. Step 3: Cross multiply
   10,931.60x = 15,085.72 × 6,215.88
4. Step 4: Simplify right side
   10,931.60x = 93,771,025.23
5. Step 5: Solve for x
   x = 93,771,025.23/10,931.60
6. Step 6: Final answer
   x = 8,577.98