Finding the Fourth Proportional to 12,981.72, 19,470.42 and 5,188.44

Step by Step Solution

1. Step 1: Write the proportion equation
   12,981.72 : 19,470.42 = 5,188.44 : x
2. Step 2: Convert to fraction form
   12,981.72/19,470.42 = 5,188.44/x
3. Step 3: Cross multiply
   12,981.72x = 19,470.42 × 5,188.44
4. Step 4: Simplify right side
   12,981.72x = 101,021,105.94
5. Step 5: Solve for x
   x = 101,021,105.94/12,981.72
6. Step 6: Final answer
   x = 7,781.80