Finding the Fourth Proportional to 105,491.38, 145,578.15 and 57,745

Step by Step Solution

1. Step 1: Write the proportion equation
   105,491.38 : 145,578.15 = 57,745 : x
2. Step 2: Convert to fraction form
   105,491.38/145,578.15 = 57,745/x
3. Step 3: Cross multiply
   105,491.38x = 145,578.15 × 57,745
4. Step 4: Simplify right side
   105,491.38x = 8,406,410,271.75
5. Step 5: Solve for x
   x = 8,406,410,271.75/105,491.38
6. Step 6: Final answer
   x = 79,688.12