Finding the Fourth Proportional to 105,436.40, 145,502.06 and 57,689.93

Step by Step Solution

1. Step 1: Write the proportion equation
   105,436.40 : 145,502.06 = 57,689.93 : x
2. Step 2: Convert to fraction form
   105,436.40/145,502.06 = 57,689.93/x
3. Step 3: Cross multiply
   105,436.40x = 145,502.06 × 57,689.93
4. Step 4: Simplify right side
   105,436.40x = 8,394,003,731.56
5. Step 5: Solve for x
   x = 8,394,003,731.56/105,436.40
6. Step 6: Final answer
   x = 79,612.01