Finding the Fourth Proportional to 30,685.48, 42,286.98 and 21,838.12

Step by Step Solution

1. Step 1: Write the proportion equation
   30,685.48 : 42,286.98 = 21,838.12 : x
2. Step 2: Convert to fraction form
   30,685.48/42,286.98 = 21,838.12/x
3. Step 3: Cross multiply
   30,685.48x = 42,286.98 × 21,838.12
4. Step 4: Simplify right side
   30,685.48x = 923,468,143.68
5. Step 5: Solve for x
   x = 923,468,143.68/30,685.48
6. Step 6: Final answer
   x = 30,094.63