Finding the Fourth Proportional to 142,638.81, 213,945.42 and 42,821.28

Step by Step Solution

1. Step 1: Write the proportion equation
   142,638.81 : 213,945.42 = 42,821.28 : x
2. Step 2: Convert to fraction form
   142,638.81/213,945.42 = 42,821.28/x
3. Step 3: Cross multiply
   142,638.81x = 213,945.42 × 42,821.28
4. Step 4: Simplify right side
   142,638.81x = 9,161,416,734.54
5. Step 5: Solve for x
   x = 9,161,416,734.54/142,638.81
6. Step 6: Final answer
   x = 64,228.08