Finding the Fourth Proportional to 105,485.88, 145,570.56 and 57,739.47

Step by Step Solution

1. Step 1: Write the proportion equation
   105,485.88 : 145,570.56 = 57,739.47 : x
2. Step 2: Convert to fraction form
   105,485.88/145,570.56 = 57,739.47/x
3. Step 3: Cross multiply
   105,485.88x = 145,570.56 × 57,739.47
4. Step 4: Simplify right side
   105,485.88x = 8,405,166,982.00
5. Step 5: Solve for x
   x = 8,405,166,982.00/105,485.88
6. Step 6: Final answer
   x = 79,680.49