Finding the Fourth Proportional to 2,139.72, 3,202.32 and 1,318.56

Step by Step Solution

1. Step 1: Write the proportion equation
   2,139.72 : 3,202.32 = 1,318.56 : x
2. Step 2: Convert to fraction form
   2,139.72/3,202.32 = 1,318.56/x
3. Step 3: Cross multiply
   2,139.72x = 3,202.32 × 1,318.56
4. Step 4: Simplify right side
   2,139.72x = 4,222,451.06
5. Step 5: Solve for x
   x = 4,222,451.06/2,139.72
6. Step 6: Final answer
   x = 1,973.37