Finding the Fourth Proportional to 2,139.47, 2,951.46 and 1,393.16

Step by Step Solution

1. Step 1: Write the proportion equation
   2,139.47 : 2,951.46 = 1,393.16 : x
2. Step 2: Convert to fraction form
   2,139.47/2,951.46 = 1,393.16/x
3. Step 3: Cross multiply
   2,139.47x = 2,951.46 × 1,393.16
4. Step 4: Simplify right side
   2,139.47x = 4,111,841.26
5. Step 5: Solve for x
   x = 4,111,841.26/2,139.47
6. Step 6: Final answer
   x = 1,921.90