Finding the Fourth Proportional to 1,401.92, 2,103.21 and 991.88

Step by Step Solution

1. Step 1: Write the proportion equation
   1,401.92 : 2,103.21 = 991.88 : x
2. Step 2: Convert to fraction form
   1,401.92/2,103.21 = 991.88/x
3. Step 3: Cross multiply
   1,401.92x = 2,103.21 × 991.88
4. Step 4: Simplify right side
   1,401.92x = 2,086,131.93
5. Step 5: Solve for x
   x = 2,086,131.93/1,401.92
6. Step 6: Final answer
   x = 1,488.05