Finding the Fourth Proportional to 1,718.50, 2,577.55 and 768.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,718.50 : 2,577.55 = 768.78 : x
2. Step 2: Convert to fraction form
   1,718.50/2,577.55 = 768.78/x
3. Step 3: Cross multiply
   1,718.50x = 2,577.55 × 768.78
4. Step 4: Simplify right side
   1,718.50x = 1,981,568.89
5. Step 5: Solve for x
   x = 1,981,568.89/1,718.50
6. Step 6: Final answer
   x = 1,153.08