Finding the Fourth Proportional to 72,021.60, 108,019.36 and 19,418.72

Step by Step Solution

1. Step 1: Write the proportion equation
   72,021.60 : 108,019.36 = 19,418.72 : x
2. Step 2: Convert to fraction form
   72,021.60/108,019.36 = 19,418.72/x
3. Step 3: Cross multiply
   72,021.60x = 108,019.36 × 19,418.72
4. Step 4: Simplify right side
   72,021.60x = 2,097,597,706.42
5. Step 5: Solve for x
   x = 2,097,597,706.42/72,021.60
6. Step 6: Final answer
   x = 29,124.56