Finding the Fourth Proportional to 2,087.74, 3,131.70 and 991.54

Step by Step Solution

1. Step 1: Write the proportion equation
   2,087.74 : 3,131.70 = 991.54 : x
2. Step 2: Convert to fraction form
   2,087.74/3,131.70 = 991.54/x
3. Step 3: Cross multiply
   2,087.74x = 3,131.70 × 991.54
4. Step 4: Simplify right side
   2,087.74x = 3,105,205.82
5. Step 5: Solve for x
   x = 3,105,205.82/2,087.74
6. Step 6: Final answer
   x = 1,487.35