Finding the Third Proportional to 142.88 and 302.63

Step by Step Solution

1. Step 1: Write the proportion equation
   142.88 : 302.63 = 302.63 : x
2. Step 2: Convert to fraction form
   142.88/302.63 = 302.63/x
3. Step 3: Cross multiply
   142.88x = 302.63 × 302.63
4. Step 4: Simplify right side
   142.88x = 91,581.89
5. Step 5: Solve for x
   x = 91,581.89/142.88
6. Step 6: Final answer
   x = 640.99