Finding the Fourth Proportional to 105,185.40, 145,161.76 and 57,443.20

Step by Step Solution

1. Step 1: Write the proportion equation
   105,185.40 : 145,161.76 = 57,443.20 : x
2. Step 2: Convert to fraction form
   105,185.40/145,161.76 = 57,443.20/x
3. Step 3: Cross multiply
   105,185.40x = 145,161.76 × 57,443.20
4. Step 4: Simplify right side
   105,185.40x = 8,338,556,012.03
5. Step 5: Solve for x
   x = 8,338,556,012.03/105,185.40
6. Step 6: Final answer
   x = 79,274.84