Finding the Fourth Proportional to 9,940.76, 13,718.66 and 5,691.50

Step by Step Solution

1. Step 1: Write the proportion equation
   9,940.76 : 13,718.66 = 5,691.50 : x
2. Step 2: Convert to fraction form
   9,940.76/13,718.66 = 5,691.50/x
3. Step 3: Cross multiply
   9,940.76x = 13,718.66 × 5,691.50
4. Step 4: Simplify right side
   9,940.76x = 78,079,656.34
5. Step 5: Solve for x
   x = 78,079,656.34/9,940.76
6. Step 6: Final answer
   x = 7,854.50