Finding the Fourth Proportional to 1,402.40, 2,105.42 and 991.73

Step by Step Solution

1. Step 1: Write the proportion equation
   1,402.40 : 2,105.42 = 991.73 : x
2. Step 2: Convert to fraction form
   1,402.40/2,105.42 = 991.73/x
3. Step 3: Cross multiply
   1,402.40x = 2,105.42 × 991.73
4. Step 4: Simplify right side
   1,402.40x = 2,088,008.18
5. Step 5: Solve for x
   x = 2,088,008.18/1,402.40
6. Step 6: Final answer
   x = 1,488.88