Finding the Fourth Proportional to 1,422.16, 2,131.84 and 680.91

Step by Step Solution

1. Step 1: Write the proportion equation
   1,422.16 : 2,131.84 = 680.91 : x
2. Step 2: Convert to fraction form
   1,422.16/2,131.84 = 680.91/x
3. Step 3: Cross multiply
   1,422.16x = 2,131.84 × 680.91
4. Step 4: Simplify right side
   1,422.16x = 1,451,597.47
5. Step 5: Solve for x
   x = 1,451,597.47/1,422.16
6. Step 6: Final answer
   x = 1,020.70