Finding the Fourth Proportional to 2,139.72, 2,953.67 and 1,394.31

Step by Step Solution

1. Step 1: Write the proportion equation
   2,139.72 : 2,953.67 = 1,394.31 : x
2. Step 2: Convert to fraction form
   2,139.72/2,953.67 = 1,394.31/x
3. Step 3: Cross multiply
   2,139.72x = 2,953.67 × 1,394.31
4. Step 4: Simplify right side
   2,139.72x = 4,118,335.72
5. Step 5: Solve for x
   x = 4,118,335.72/2,139.72
6. Step 6: Final answer
   x = 1,924.71