Finding the Fourth Proportional to 2,592.81, 3,888.50 and 861.45

Step by Step Solution

1. Step 1: Write the proportion equation
   2,592.81 : 3,888.50 = 861.45 : x
2. Step 2: Convert to fraction form
   2,592.81/3,888.50 = 861.45/x
3. Step 3: Cross multiply
   2,592.81x = 3,888.50 × 861.45
4. Step 4: Simplify right side
   2,592.81x = 3,349,744.02
5. Step 5: Solve for x
   x = 3,349,744.02/2,592.81
6. Step 6: Final answer
   x = 1,291.94