Finding the Fourth Proportional to 1,978.20, 2,966.60 and 679.37

Step by Step Solution

1. Step 1: Write the proportion equation
   1,978.20 : 2,966.60 = 679.37 : x
2. Step 2: Convert to fraction form
   1,978.20/2,966.60 = 679.37/x
3. Step 3: Cross multiply
   1,978.20x = 2,966.60 × 679.37
4. Step 4: Simplify right side
   1,978.20x = 2,015,405.91
5. Step 5: Solve for x
   x = 2,015,405.91/1,978.20
6. Step 6: Final answer
   x = 1,018.81