Finding the Fourth Proportional to 51,399.72, 77,128.72 and 20,256.84

Step by Step Solution

1. Step 1: Write the proportion equation
   51,399.72 : 77,128.72 = 20,256.84 : x
2. Step 2: Convert to fraction form
   51,399.72/77,128.72 = 20,256.84/x
3. Step 3: Cross multiply
   51,399.72x = 77,128.72 × 20,256.84
4. Step 4: Simplify right side
   51,399.72x = 1,562,384,140.44
5. Step 5: Solve for x
   x = 1,562,384,140.44/51,399.72
6. Step 6: Final answer
   x = 30,396.74