Finding the Third Proportional to 66.75 and 72.50

Step by Step Solution

1. Step 1: Write the proportion equation
   66.75 : 72.50 = 72.50 : x
2. Step 2: Convert to fraction form
   66.75/72.50 = 72.50/x
3. Step 3: Cross multiply
   66.75x = 72.50 × 72.50
4. Step 4: Simplify right side
   66.75x = 5,256.25
5. Step 5: Solve for x
   x = 5,256.25/66.75
6. Step 6: Final answer
   x = 78.75