Finding the Fourth Proportional to 7,865.91, 10,856.01 and 7,201.57

Step by Step Solution

1. Step 1: Write the proportion equation
   7,865.91 : 10,856.01 = 7,201.57 : x
2. Step 2: Convert to fraction form
   7,865.91/10,856.01 = 7,201.57/x
3. Step 3: Cross multiply
   7,865.91x = 10,856.01 × 7,201.57
4. Step 4: Simplify right side
   7,865.91x = 78,180,315.94
5. Step 5: Solve for x
   x = 78,180,315.94/7,865.91
6. Step 6: Final answer
   x = 9,939.13