Finding the Fourth Proportional to 2,087.16, 3,133.91 and 1,311.99

Step by Step Solution

1. Step 1: Write the proportion equation
   2,087.16 : 3,133.91 = 1,311.99 : x
2. Step 2: Convert to fraction form
   2,087.16/3,133.91 = 1,311.99/x
3. Step 3: Cross multiply
   2,087.16x = 3,133.91 × 1,311.99
4. Step 4: Simplify right side
   2,087.16x = 4,111,658.58
5. Step 5: Solve for x
   x = 4,111,658.58/2,087.16
6. Step 6: Final answer
   x = 1,969.98