Finding the Fourth Proportional to 1,978.74, 2,966.28 and 679.92

Step by Step Solution

1. Step 1: Write the proportion equation
   1,978.74 : 2,966.28 = 679.92 : x
2. Step 2: Convert to fraction form
   1,978.74/2,966.28 = 679.92/x
3. Step 3: Cross multiply
   1,978.74x = 2,966.28 × 679.92
4. Step 4: Simplify right side
   1,978.74x = 2,016,833.10
5. Step 5: Solve for x
   x = 2,016,833.10/1,978.74
6. Step 6: Final answer
   x = 1,019.25