Finding the Third Proportional to 3,920.50 and 8,570.50

Step by Step Solution

1. Step 1: Write the proportion equation
   3,920.50 : 8,570.50 = 8,570.50 : x
2. Step 2: Convert to fraction form
   3,920.50/8,570.50 = 8,570.50/x
3. Step 3: Cross multiply
   3,920.50x = 8,570.50 × 8,570.50
4. Step 4: Simplify right side
   3,920.50x = 73,453,470.25
5. Step 5: Solve for x
   x = 73,453,470.25/3,920.50
6. Step 6: Final answer
   x = 18,735.74