Finding the Fourth Proportional to 2,420.15, 3,630.77 and 776.69

Step by Step Solution

1. Step 1: Write the proportion equation
   2,420.15 : 3,630.77 = 776.69 : x
2. Step 2: Convert to fraction form
   2,420.15/3,630.77 = 776.69/x
3. Step 3: Cross multiply
   2,420.15x = 3,630.77 × 776.69
4. Step 4: Simplify right side
   2,420.15x = 2,819,960.71
5. Step 5: Solve for x
   x = 2,819,960.71/2,420.15
6. Step 6: Final answer
   x = 1,165.20