Finding the Fourth Proportional to 72,128.20, 108,197.72 and 19,536.88

Step by Step Solution

1. Step 1: Write the proportion equation
   72,128.20 : 108,197.72 = 19,536.88 : x
2. Step 2: Convert to fraction form
   72,128.20/108,197.72 = 19,536.88/x
3. Step 3: Cross multiply
   72,128.20x = 108,197.72 × 19,536.88
4. Step 4: Simplify right side
   72,128.20x = 2,113,845,871.91
5. Step 5: Solve for x
   x = 2,113,845,871.91/72,128.20
6. Step 6: Final answer
   x = 29,306.79