Finding the Fourth Proportional to 31,738.56, 43,779.42 and 20,422.80

Step by Step Solution

1. Step 1: Write the proportion equation
   31,738.56 : 43,779.42 = 20,422.80 : x
2. Step 2: Convert to fraction form
   31,738.56/43,779.42 = 20,422.80/x
3. Step 3: Cross multiply
   31,738.56x = 43,779.42 × 20,422.80
4. Step 4: Simplify right side
   31,738.56x = 894,098,338.78
5. Step 5: Solve for x
   x = 894,098,338.78/31,738.56
6. Step 6: Final answer
   x = 28,170.73