Finding the Fourth Proportional to 2,580.51, 3,870.98 and 825.77

Step by Step Solution

1. Step 1: Write the proportion equation
   2,580.51 : 3,870.98 = 825.77 : x
2. Step 2: Convert to fraction form
   2,580.51/3,870.98 = 825.77/x
3. Step 3: Cross multiply
   2,580.51x = 3,870.98 × 825.77
4. Step 4: Simplify right side
   2,580.51x = 3,196,515.67
5. Step 5: Solve for x
   x = 3,196,515.67/2,580.51
6. Step 6: Final answer
   x = 1,238.71