Finding the Third Proportional to 65.90 and 143.18

Step by Step Solution

1. Step 1: Write the proportion equation
   65.90 : 143.18 = 143.18 : x
2. Step 2: Convert to fraction form
   65.90/143.18 = 143.18/x
3. Step 3: Cross multiply
   65.90x = 143.18 × 143.18
4. Step 4: Simplify right side
   65.90x = 20,500.74
5. Step 5: Solve for x
   x = 20,500.74/65.90
6. Step 6: Final answer
   x = 311.11