Finding the Fourth Proportional to 42,300.90, 63,445.84 and 20,128.38

Step by Step Solution

1. Step 1: Write the proportion equation
   42,300.90 : 63,445.84 = 20,128.38 : x
2. Step 2: Convert to fraction form
   42,300.90/63,445.84 = 20,128.38/x
3. Step 3: Cross multiply
   42,300.90x = 63,445.84 × 20,128.38
4. Step 4: Simplify right side
   42,300.90x = 1,277,061,976.94
5. Step 5: Solve for x
   x = 1,277,061,976.94/42,300.90
6. Step 6: Final answer
   x = 30,189.95