Finding the Fourth Proportional to 13,722.42, 18,936.90 and 7,434.78

Step by Step Solution

1. Step 1: Write the proportion equation
   13,722.42 : 18,936.90 = 7,434.78 : x
2. Step 2: Convert to fraction form
   13,722.42/18,936.90 = 7,434.78/x
3. Step 3: Cross multiply
   13,722.42x = 18,936.90 × 7,434.78
4. Step 4: Simplify right side
   13,722.42x = 140,791,685.38
5. Step 5: Solve for x
   x = 140,791,685.38/13,722.42
6. Step 6: Final answer
   x = 10,259.97