Finding the Fourth Proportional to 12,900.42, 17,802.78 and 7,236.43

Step by Step Solution

1. Step 1: Write the proportion equation
   12,900.42 : 17,802.78 = 7,236.43 : x
2. Step 2: Convert to fraction form
   12,900.42/17,802.78 = 7,236.43/x
3. Step 3: Cross multiply
   12,900.42x = 17,802.78 × 7,236.43
4. Step 4: Simplify right side
   12,900.42x = 128,828,571.28
5. Step 5: Solve for x
   x = 128,828,571.28/12,900.42
6. Step 6: Final answer
   x = 9,986.39