Finding the Fourth Proportional to 1,978.21, 2,964.48 and 866.28

Step by Step Solution

1. Step 1: Write the proportion equation
   1,978.21 : 2,964.48 = 866.28 : x
2. Step 2: Convert to fraction form
   1,978.21/2,964.48 = 866.28/x
3. Step 3: Cross multiply
   1,978.21x = 2,964.48 × 866.28
4. Step 4: Simplify right side
   1,978.21x = 2,568,069.73
5. Step 5: Solve for x
   x = 2,568,069.73/1,978.21
6. Step 6: Final answer
   x = 1,298.18