Finding the Fourth Proportional to 105,521.72, 145,614.38 and 57,765.87

Step by Step Solution

1. Step 1: Write the proportion equation
   105,521.72 : 145,614.38 = 57,765.87 : x
2. Step 2: Convert to fraction form
   105,521.72/145,614.38 = 57,765.87/x
3. Step 3: Cross multiply
   105,521.72x = 145,614.38 × 57,765.87
4. Step 4: Simplify right side
   105,521.72x = 8,411,541,056.38
5. Step 5: Solve for x
   x = 8,411,541,056.38/105,521.72
6. Step 6: Final answer
   x = 79,713.84