Finding the Fourth Proportional to 10,860.56, 16,265.52 and 7,931.60

Step by Step Solution

1. Step 1: Write the proportion equation
   10,860.56 : 16,265.52 = 7,931.60 : x
2. Step 2: Convert to fraction form
   10,860.56/16,265.52 = 7,931.60/x
3. Step 3: Cross multiply
   10,860.56x = 16,265.52 × 7,931.60
4. Step 4: Simplify right side
   10,860.56x = 129,011,598.43
5. Step 5: Solve for x
   x = 129,011,598.43/10,860.56
6. Step 6: Final answer
   x = 11,878.91