Finding the Fourth Proportional to 1,685.72, 2,326.28 and 939.71

Step by Step Solution

1. Step 1: Write the proportion equation
   1,685.72 : 2,326.28 = 939.71 : x
2. Step 2: Convert to fraction form
   1,685.72/2,326.28 = 939.71/x
3. Step 3: Cross multiply
   1,685.72x = 2,326.28 × 939.71
4. Step 4: Simplify right side
   1,685.72x = 2,186,012.25
5. Step 5: Solve for x
   x = 2,186,012.25/1,685.72
6. Step 6: Final answer
   x = 1,296.79