Finding the Third Proportional to 2,560.78 and 3,915.56

Step by Step Solution

1. Step 1: Write the proportion equation
   2,560.78 : 3,915.56 = 3,915.56 : x
2. Step 2: Convert to fraction form
   2,560.78/3,915.56 = 3,915.56/x
3. Step 3: Cross multiply
   2,560.78x = 3,915.56 × 3,915.56
4. Step 4: Simplify right side
   2,560.78x = 15,331,629.69
5. Step 5: Solve for x
   x = 15,331,629.69/2,560.78
6. Step 6: Final answer
   x = 5,987.09