Finding the Fourth Proportional to 2,615.76, 3,924.18 and 766.80

Step by Step Solution

1. Step 1: Write the proportion equation
   2,615.76 : 3,924.18 = 766.80 : x
2. Step 2: Convert to fraction form
   2,615.76/3,924.18 = 766.80/x
3. Step 3: Cross multiply
   2,615.76x = 3,924.18 × 766.80
4. Step 4: Simplify right side
   2,615.76x = 3,009,061.22
5. Step 5: Solve for x
   x = 3,009,061.22/2,615.76
6. Step 6: Final answer
   x = 1,150.36