Finding the Third Proportional to 64.69 and 90.63

Step by Step Solution

1. Step 1: Write the proportion equation
   64.69 : 90.63 = 90.63 : x
2. Step 2: Convert to fraction form
   64.69/90.63 = 90.63/x
3. Step 3: Cross multiply
   64.69x = 90.63 × 90.63
4. Step 4: Simplify right side
   64.69x = 8,212.89
5. Step 5: Solve for x
   x = 8,212.89/64.69
6. Step 6: Final answer
   x = 126.96