Finding the Fourth Proportional to 76,719.72, 105,872.91 and 42,728.58

Step by Step Solution

1. Step 1: Write the proportion equation
   76,719.72 : 105,872.91 = 42,728.58 : x
2. Step 2: Convert to fraction form
   76,719.72/105,872.91 = 42,728.58/x
3. Step 3: Cross multiply
   76,719.72x = 105,872.91 × 42,728.58
4. Step 4: Simplify right side
   76,719.72x = 4,523,799,104.77
5. Step 5: Solve for x
   x = 4,523,799,104.77/76,719.72
6. Step 6: Final answer
   x = 58,965.27