Finding the Fourth Proportional to 2,088.96, 3,131.28 and 991.68

Step by Step Solution

1. Step 1: Write the proportion equation
   2,088.96 : 3,131.28 = 991.68 : x
2. Step 2: Convert to fraction form
   2,088.96/3,131.28 = 991.68/x
3. Step 3: Cross multiply
   2,088.96x = 3,131.28 × 991.68
4. Step 4: Simplify right side
   2,088.96x = 3,105,227.75
5. Step 5: Solve for x
   x = 3,105,227.75/2,088.96
6. Step 6: Final answer
   x = 1,486.49