Finding the Fourth Proportional to 20,290.72, 30,442.56 and 8,613.76

Step by Step Solution

1. Step 1: Write the proportion equation
   20,290.72 : 30,442.56 = 8,613.76 : x
2. Step 2: Convert to fraction form
   20,290.72/30,442.56 = 8,613.76/x
3. Step 3: Cross multiply
   20,290.72x = 30,442.56 × 8,613.76
4. Step 4: Simplify right side
   20,290.72x = 262,224,905.63
5. Step 5: Solve for x
   x = 262,224,905.63/20,290.72
6. Step 6: Final answer
   x = 12,923.39