Finding the Fourth Proportional to 2,140.86, 3,211.79 and 908.31

Step by Step Solution

1. Step 1: Write the proportion equation
   2,140.86 : 3,211.79 = 908.31 : x
2. Step 2: Convert to fraction form
   2,140.86/3,211.79 = 908.31/x
3. Step 3: Cross multiply
   2,140.86x = 3,211.79 × 908.31
4. Step 4: Simplify right side
   2,140.86x = 2,917,308.48
5. Step 5: Solve for x
   x = 2,917,308.48/2,140.86
6. Step 6: Final answer
   x = 1,362.68