Finding the Third Proportional to 13.50 and 91.50

Step by Step Solution

1. Step 1: Write the proportion equation
   13.50 : 91.50 = 91.50 : x
2. Step 2: Convert to fraction form
   13.50/91.50 = 91.50/x
3. Step 3: Cross multiply
   13.50x = 91.50 × 91.50
4. Step 4: Simplify right side
   13.50x = 8,372.25
5. Step 5: Solve for x
   x = 8,372.25/13.50
6. Step 6: Final answer
   x = 620.17