Finding the Fourth Proportional to 1,986.02, 2,978.46 and 831.50

Step by Step Solution

1. Step 1: Write the proportion equation
   1,986.02 : 2,978.46 = 831.50 : x
2. Step 2: Convert to fraction form
   1,986.02/2,978.46 = 831.50/x
3. Step 3: Cross multiply
   1,986.02x = 2,978.46 × 831.50
4. Step 4: Simplify right side
   1,986.02x = 2,476,589.49
5. Step 5: Solve for x
   x = 2,476,589.49/1,986.02
6. Step 6: Final answer
   x = 1,247.01