Finding the Third Proportional to 3,899.39 and 8,556.89

Step by Step Solution

1. Step 1: Write the proportion equation
   3,899.39 : 8,556.89 = 8,556.89 : x
2. Step 2: Convert to fraction form
   3,899.39/8,556.89 = 8,556.89/x
3. Step 3: Cross multiply
   3,899.39x = 8,556.89 × 8,556.89
4. Step 4: Simplify right side
   3,899.39x = 73,220,377.17
5. Step 5: Solve for x
   x = 73,220,377.17/3,899.39
6. Step 6: Final answer
   x = 18,777.39