Finding the Fourth Proportional to 105,145.42, 145,100.94 and 57,398.80

Step by Step Solution

1. Step 1: Write the proportion equation
   105,145.42 : 145,100.94 = 57,398.80 : x
2. Step 2: Convert to fraction form
   105,145.42/145,100.94 = 57,398.80/x
3. Step 3: Cross multiply
   105,145.42x = 145,100.94 × 57,398.80
4. Step 4: Simplify right side
   105,145.42x = 8,328,619,834.87
5. Step 5: Solve for x
   x = 8,328,619,834.87/105,145.42
6. Step 6: Final answer
   x = 79,210.49