Finding the Fourth Proportional to 12,802.78, 19,206.78 and 7,258.60

Step by Step Solution

1. Step 1: Write the proportion equation
   12,802.78 : 19,206.78 = 7,258.60 : x
2. Step 2: Convert to fraction form
   12,802.78/19,206.78 = 7,258.60/x
3. Step 3: Cross multiply
   12,802.78x = 19,206.78 × 7,258.60
4. Step 4: Simplify right side
   12,802.78x = 139,414,333.31
5. Step 5: Solve for x
   x = 139,414,333.31/12,802.78
6. Step 6: Final answer
   x = 10,889.38