Finding the Fourth Proportional to 1,488.49, 2,231.17 and 611.57

Step by Step Solution

1. Step 1: Write the proportion equation
   1,488.49 : 2,231.17 = 611.57 : x
2. Step 2: Convert to fraction form
   1,488.49/2,231.17 = 611.57/x
3. Step 3: Cross multiply
   1,488.49x = 2,231.17 × 611.57
4. Step 4: Simplify right side
   1,488.49x = 1,364,520.69
5. Step 5: Solve for x
   x = 1,364,520.69/1,488.49
6. Step 6: Final answer
   x = 916.72