Finding the Fourth Proportional to 1,086.78, 1,628.45 and 675.30

Step by Step Solution

1. Step 1: Write the proportion equation
   1,086.78 : 1,628.45 = 675.30 : x
2. Step 2: Convert to fraction form
   1,086.78/1,628.45 = 675.30/x
3. Step 3: Cross multiply
   1,086.78x = 1,628.45 × 675.30
4. Step 4: Simplify right side
   1,086.78x = 1,099,692.29
5. Step 5: Solve for x
   x = 1,099,692.29/1,086.78
6. Step 6: Final answer
   x = 1,011.88