Finding the Fourth Proportional to 30,741.72, 42,412.17 and 20,137.20

Step by Step Solution

1. Step 1: Write the proportion equation
   30,741.72 : 42,412.17 = 20,137.20 : x
2. Step 2: Convert to fraction form
   30,741.72/42,412.17 = 20,137.20/x
3. Step 3: Cross multiply
   30,741.72x = 42,412.17 × 20,137.20
4. Step 4: Simplify right side
   30,741.72x = 854,062,349.72
5. Step 5: Solve for x
   x = 854,062,349.72/30,741.72
6. Step 6: Final answer
   x = 27,781.87