Finding the Fourth Proportional to 13,766.42, 18,997.89 and 7,478.80

Step by Step Solution

1. Step 1: Write the proportion equation
   13,766.42 : 18,997.89 = 7,478.80 : x
2. Step 2: Convert to fraction form
   13,766.42/18,997.89 = 7,478.80/x
3. Step 3: Cross multiply
   13,766.42x = 18,997.89 × 7,478.80
4. Step 4: Simplify right side
   13,766.42x = 142,081,419.73
5. Step 5: Solve for x
   x = 142,081,419.73/13,766.42
6. Step 6: Final answer
   x = 10,320.87