Finding the Fourth Proportional to 1,978.80, 2,968.68 and 680.28

Step by Step Solution

1. Step 1: Write the proportion equation
   1,978.80 : 2,968.68 = 680.28 : x
2. Step 2: Convert to fraction form
   1,978.80/2,968.68 = 680.28/x
3. Step 3: Cross multiply
   1,978.80x = 2,968.68 × 680.28
4. Step 4: Simplify right side
   1,978.80x = 2,019,533.63
5. Step 5: Solve for x
   x = 2,019,533.63/1,978.80
6. Step 6: Final answer
   x = 1,020.59