Finding the Fourth Proportional to 1,398.46, 1,929.77 and 800.88

Step by Step Solution

1. Step 1: Write the proportion equation
   1,398.46 : 1,929.77 = 800.88 : x
2. Step 2: Convert to fraction form
   1,398.46/1,929.77 = 800.88/x
3. Step 3: Cross multiply
   1,398.46x = 1,929.77 × 800.88
4. Step 4: Simplify right side
   1,398.46x = 1,545,515.89
5. Step 5: Solve for x
   x = 1,545,515.89/1,398.46
6. Step 6: Final answer
   x = 1,105.16