Finding the Fourth Proportional to 22,131.42, 30,571.20 and 20,556.78

Step by Step Solution

1. Step 1: Write the proportion equation
   22,131.42 : 30,571.20 = 20,556.78 : x
2. Step 2: Convert to fraction form
   22,131.42/30,571.20 = 20,556.78/x
3. Step 3: Cross multiply
   22,131.42x = 30,571.20 × 20,556.78
4. Step 4: Simplify right side
   22,131.42x = 628,445,432.74
5. Step 5: Solve for x
   x = 628,445,432.74/22,131.42
6. Step 6: Final answer
   x = 28,396.07