Finding the Third Proportional to 65,991 and 89,656.50

Step by Step Solution

1. Step 1: Write the proportion equation
   65,991 : 89,656.50 = 89,656.50 : x
2. Step 2: Convert to fraction form
   65,991/89,656.50 = 89,656.50/x
3. Step 3: Cross multiply
   65,991x = 89,656.50 × 89,656.50
4. Step 4: Simplify right side
   65,991x = 8,038,287,992.25
5. Step 5: Solve for x
   x = 8,038,287,992.25/65,991
6. Step 6: Final answer
   x = 121,808.85