Finding the Fourth Proportional to 10,581.78, 15,869.42 and 7,315.86

Step by Step Solution

1. Step 1: Write the proportion equation
   10,581.78 : 15,869.42 = 7,315.86 : x
2. Step 2: Convert to fraction form
   10,581.78/15,869.42 = 7,315.86/x
3. Step 3: Cross multiply
   10,581.78x = 15,869.42 × 7,315.86
4. Step 4: Simplify right side
   10,581.78x = 116,098,455.00
5. Step 5: Solve for x
   x = 116,098,455.00/10,581.78
6. Step 6: Final answer
   x = 10,971.54