Finding the Fourth Proportional to 28,512.82, 42,780.18 and 20,087.42

Step by Step Solution

1. Step 1: Write the proportion equation
   28,512.82 : 42,780.18 = 20,087.42 : x
2. Step 2: Convert to fraction form
   28,512.82/42,780.18 = 20,087.42/x
3. Step 3: Cross multiply
   28,512.82x = 42,780.18 × 20,087.42
4. Step 4: Simplify right side
   28,512.82x = 859,343,443.34
5. Step 5: Solve for x
   x = 859,343,443.34/28,512.82
6. Step 6: Final answer
   x = 30,138.85