Finding the Fourth Proportional to 8,298.78, 12,458.70 and 7,136.16

Step by Step Solution

1. Step 1: Write the proportion equation
   8,298.78 : 12,458.70 = 7,136.16 : x
2. Step 2: Convert to fraction form
   8,298.78/12,458.70 = 7,136.16/x
3. Step 3: Cross multiply
   8,298.78x = 12,458.70 × 7,136.16
4. Step 4: Simplify right side
   8,298.78x = 88,907,276.59
5. Step 5: Solve for x
   x = 88,907,276.59/8,298.78
6. Step 6: Final answer
   x = 10,713.29