Finding the Fourth Proportional to 1,685.86, 2,326.27 and 939.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,685.86 : 2,326.27 = 939.78 : x
2. Step 2: Convert to fraction form
   1,685.86/2,326.27 = 939.78/x
3. Step 3: Cross multiply
   1,685.86x = 2,326.27 × 939.78
4. Step 4: Simplify right side
   1,685.86x = 2,186,182.02
5. Step 5: Solve for x
   x = 2,186,182.02/1,685.86
6. Step 6: Final answer
   x = 1,296.78