Finding the Fourth Proportional to 12,978.50, 19,498.89 and 8,307.63

Step by Step Solution

1. Step 1: Write the proportion equation
   12,978.50 : 19,498.89 = 8,307.63 : x
2. Step 2: Convert to fraction form
   12,978.50/19,498.89 = 8,307.63/x
3. Step 3: Cross multiply
   12,978.50x = 19,498.89 × 8,307.63
4. Step 4: Simplify right side
   12,978.50x = 161,989,594.68
5. Step 5: Solve for x
   x = 161,989,594.68/12,978.50
6. Step 6: Final answer
   x = 12,481.39