Finding the Fourth Proportional to 20,445.48, 30,689.69 and 18,120.38

Step by Step Solution

1. Step 1: Write the proportion equation
   20,445.48 : 30,689.69 = 18,120.38 : x
2. Step 2: Convert to fraction form
   20,445.48/30,689.69 = 18,120.38/x
3. Step 3: Cross multiply
   20,445.48x = 30,689.69 × 18,120.38
4. Step 4: Simplify right side
   20,445.48x = 556,108,600.83
5. Step 5: Solve for x
   x = 556,108,600.83/20,445.48
6. Step 6: Final answer
   x = 27,199.59