Finding the Fourth Proportional to 3,111.88, 4,668.16 and 920.61

Step by Step Solution

1. Step 1: Write the proportion equation
   3,111.88 : 4,668.16 = 920.61 : x
2. Step 2: Convert to fraction form
   3,111.88/4,668.16 = 920.61/x
3. Step 3: Cross multiply
   3,111.88x = 4,668.16 × 920.61
4. Step 4: Simplify right side
   3,111.88x = 4,297,554.78
5. Step 5: Solve for x
   x = 4,297,554.78/3,111.88
6. Step 6: Final answer
   x = 1,381.02