Finding the Fourth Proportional to 2,580.78, 3,868.59 and 936.89

Step by Step Solution

1. Step 1: Write the proportion equation
   2,580.78 : 3,868.59 = 936.89 : x
2. Step 2: Convert to fraction form
   2,580.78/3,868.59 = 936.89/x
3. Step 3: Cross multiply
   2,580.78x = 3,868.59 × 936.89
4. Step 4: Simplify right side
   2,580.78x = 3,624,441.96
5. Step 5: Solve for x
   x = 3,624,441.96/2,580.78
6. Step 6: Final answer
   x = 1,404.40