Finding the Third Proportional to 65,641.75 and 72,408.50

Step by Step Solution

1. Step 1: Write the proportion equation
   65,641.75 : 72,408.50 = 72,408.50 : x
2. Step 2: Convert to fraction form
   65,641.75/72,408.50 = 72,408.50/x
3. Step 3: Cross multiply
   65,641.75x = 72,408.50 × 72,408.50
4. Step 4: Simplify right side
   65,641.75x = 5,242,990,872.25
5. Step 5: Solve for x
   x = 5,242,990,872.25/65,641.75
6. Step 6: Final answer
   x = 79,872.81