Finding the Third Proportional to 64.80 and 141.72

Step by Step Solution

1. Step 1: Write the proportion equation
   64.80 : 141.72 = 141.72 : x
2. Step 2: Convert to fraction form
   64.80/141.72 = 141.72/x
3. Step 3: Cross multiply
   64.80x = 141.72 × 141.72
4. Step 4: Simplify right side
   64.80x = 20,084.20
5. Step 5: Solve for x
   x = 20,084.20/64.80
6. Step 6: Final answer
   x = 309.96