Finding the Fourth Proportional to 9,940.78, 13,718.64 and 5,692.60

Step by Step Solution

1. Step 1: Write the proportion equation
   9,940.78 : 13,718.64 = 5,692.60 : x
2. Step 2: Convert to fraction form
   9,940.78/13,718.64 = 5,692.60/x
3. Step 3: Cross multiply
   9,940.78x = 13,718.64 × 5,692.60
4. Step 4: Simplify right side
   9,940.78x = 78,094,736.54
5. Step 5: Solve for x
   x = 78,094,736.54/9,940.78
6. Step 6: Final answer
   x = 7,856.00