Finding the Fourth Proportional to 2,231.39, 3,079.34 and 1,223.12

Step by Step Solution

1. Step 1: Write the proportion equation
   2,231.39 : 3,079.34 = 1,223.12 : x
2. Step 2: Convert to fraction form
   2,231.39/3,079.34 = 1,223.12/x
3. Step 3: Cross multiply
   2,231.39x = 3,079.34 × 1,223.12
4. Step 4: Simplify right side
   2,231.39x = 3,766,392.38
5. Step 5: Solve for x
   x = 3,766,392.38/2,231.39
6. Step 6: Final answer
   x = 1,687.92