Finding the Fourth Proportional to 58,719.39, 80,920.89 and 57,639.76

Step by Step Solution

1. Step 1: Write the proportion equation
   58,719.39 : 80,920.89 = 57,639.76 : x
2. Step 2: Convert to fraction form
   58,719.39/80,920.89 = 57,639.76/x
3. Step 3: Cross multiply
   58,719.39x = 80,920.89 × 57,639.76
4. Step 4: Simplify right side
   58,719.39x = 4,664,260,678.59
5. Step 5: Solve for x
   x = 4,664,260,678.59/58,719.39
6. Step 6: Final answer
   x = 79,433.06