Finding the Fourth Proportional to 105,128.55, 145,079.51 and 57,386.07

Step by Step Solution

1. Step 1: Write the proportion equation
   105,128.55 : 145,079.51 = 57,386.07 : x
2. Step 2: Convert to fraction form
   105,128.55/145,079.51 = 57,386.07/x
3. Step 3: Cross multiply
   105,128.55x = 145,079.51 × 57,386.07
4. Step 4: Simplify right side
   105,128.55x = 8,325,542,629.50
5. Step 5: Solve for x
   x = 8,325,542,629.50/105,128.55
6. Step 6: Final answer
   x = 79,193.93