Finding the Fourth Proportional to 1,412.05, 2,116.02 and 680.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,412.05 : 2,116.02 = 680.78 : x
2. Step 2: Convert to fraction form
   1,412.05/2,116.02 = 680.78/x
3. Step 3: Cross multiply
   1,412.05x = 2,116.02 × 680.78
4. Step 4: Simplify right side
   1,412.05x = 1,440,544.10
5. Step 5: Solve for x
   x = 1,440,544.10/1,412.05
6. Step 6: Final answer
   x = 1,020.18