Finding the Fourth Proportional to 2,710.91, 4,066.64 and 861.55

Step by Step Solution

1. Step 1: Write the proportion equation
   2,710.91 : 4,066.64 = 861.55 : x
2. Step 2: Convert to fraction form
   2,710.91/4,066.64 = 861.55/x
3. Step 3: Cross multiply
   2,710.91x = 4,066.64 × 861.55
4. Step 4: Simplify right side
   2,710.91x = 3,503,613.69
5. Step 5: Solve for x
   x = 3,503,613.69/2,710.91
6. Step 6: Final answer
   x = 1,292.41