Finding the Fourth Proportional to 30,498.90, 42,121.38 and 20,963.98

Step by Step Solution

1. Step 1: Write the proportion equation
   30,498.90 : 42,121.38 = 20,963.98 : x
2. Step 2: Convert to fraction form
   30,498.90/42,121.38 = 20,963.98/x
3. Step 3: Cross multiply
   30,498.90x = 42,121.38 × 20,963.98
4. Step 4: Simplify right side
   30,498.90x = 883,031,767.89
5. Step 5: Solve for x
   x = 883,031,767.89/30,498.90
6. Step 6: Final answer
   x = 28,952.91