Finding the Fourth Proportional to 105,615.76, 145,749.72 and 57,870.92

Step by Step Solution

1. Step 1: Write the proportion equation
   105,615.76 : 145,749.72 = 57,870.92 : x
2. Step 2: Convert to fraction form
   105,615.76/145,749.72 = 57,870.92/x
3. Step 3: Cross multiply
   105,615.76x = 145,749.72 × 57,870.92
4. Step 4: Simplify right side
   105,615.76x = 8,434,670,386.14
5. Step 5: Solve for x
   x = 8,434,670,386.14/105,615.76
6. Step 6: Final answer
   x = 79,861.85