Finding the Fourth Proportional to 12,981.76, 19,471.68 and 5,185.60

Step by Step Solution

1. Step 1: Write the proportion equation
   12,981.76 : 19,471.68 = 5,185.60 : x
2. Step 2: Convert to fraction form
   12,981.76/19,471.68 = 5,185.60/x
3. Step 3: Cross multiply
   12,981.76x = 19,471.68 × 5,185.60
4. Step 4: Simplify right side
   12,981.76x = 100,972,343.81
5. Step 5: Solve for x
   x = 100,972,343.81/12,981.76
6. Step 6: Final answer
   x = 7,778.02