Finding the Fourth Proportional to 105,419.72, 145,477.98 and 57,672.47

Step by Step Solution

1. Step 1: Write the proportion equation
   105,419.72 : 145,477.98 = 57,672.47 : x
2. Step 2: Convert to fraction form
   105,419.72/145,477.98 = 57,672.47/x
3. Step 3: Cross multiply
   105,419.72x = 145,477.98 × 57,672.47
4. Step 4: Simplify right side
   105,419.72x = 8,390,073,709.82
5. Step 5: Solve for x
   x = 8,390,073,709.82/105,419.72
6. Step 6: Final answer
   x = 79,587.33