Finding the Fourth Proportional to 1,421.82, 1,961.51 and 831.33

Step by Step Solution

1. Step 1: Write the proportion equation
   1,421.82 : 1,961.51 = 831.33 : x
2. Step 2: Convert to fraction form
   1,421.82/1,961.51 = 831.33/x
3. Step 3: Cross multiply
   1,421.82x = 1,961.51 × 831.33
4. Step 4: Simplify right side
   1,421.82x = 1,630,657.95
5. Step 5: Solve for x
   x = 1,630,657.95/1,421.82
6. Step 6: Final answer
   x = 1,146.88