Finding the Third Proportional to 2,587.57 and 3,986.72

Step by Step Solution

1. Step 1: Write the proportion equation
   2,587.57 : 3,986.72 = 3,986.72 : x
2. Step 2: Convert to fraction form
   2,587.57/3,986.72 = 3,986.72/x
3. Step 3: Cross multiply
   2,587.57x = 3,986.72 × 3,986.72
4. Step 4: Simplify right side
   2,587.57x = 15,893,926.39
5. Step 5: Solve for x
   x = 15,893,926.39/2,587.57
6. Step 6: Final answer
   x = 6,142.41