Finding the Fourth Proportional to 2,939.16, 4,409.39 and 991.31

Step by Step Solution

1. Step 1: Write the proportion equation
   2,939.16 : 4,409.39 = 991.31 : x
2. Step 2: Convert to fraction form
   2,939.16/4,409.39 = 991.31/x
3. Step 3: Cross multiply
   2,939.16x = 4,409.39 × 991.31
4. Step 4: Simplify right side
   2,939.16x = 4,371,085.90
5. Step 5: Solve for x
   x = 4,371,085.90/2,939.16
6. Step 6: Final answer
   x = 1,487.19