Finding the Third Proportional to 2,587.78 and 5,645.53

Step by Step Solution

1. Step 1: Write the proportion equation
   2,587.78 : 5,645.53 = 5,645.53 : x
2. Step 2: Convert to fraction form
   2,587.78/5,645.53 = 5,645.53/x
3. Step 3: Cross multiply
   2,587.78x = 5,645.53 × 5,645.53
4. Step 4: Simplify right side
   2,587.78x = 31,872,023.09
5. Step 5: Solve for x
   x = 31,872,023.09/2,587.78
6. Step 6: Final answer
   x = 12,316.35