Finding the Third Proportional to 1,686 and 3,641.50

Step by Step Solution

1. Step 1: Write the proportion equation
   1,686 : 3,641.50 = 3,641.50 : x
2. Step 2: Convert to fraction form
   1,686/3,641.50 = 3,641.50/x
3. Step 3: Cross multiply
   1,686x = 3,641.50 × 3,641.50
4. Step 4: Simplify right side
   1,686x = 13,260,522.25
5. Step 5: Solve for x
   x = 13,260,522.25/1,686
6. Step 6: Final answer
   x = 7,865.08