Finding the Fourth Proportional to 1,098.72, 1,649.37 and 867.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,098.72 : 1,649.37 = 867.78 : x
2. Step 2: Convert to fraction form
   1,098.72/1,649.37 = 867.78/x
3. Step 3: Cross multiply
   1,098.72x = 1,649.37 × 867.78
4. Step 4: Simplify right side
   1,098.72x = 1,431,290.30
5. Step 5: Solve for x
   x = 1,431,290.30/1,098.72
6. Step 6: Final answer
   x = 1,302.69