Finding the Third Proportional to 143.30 and 313.59

Step by Step Solution

1. Step 1: Write the proportion equation
   143.30 : 313.59 = 313.59 : x
2. Step 2: Convert to fraction form
   143.30/313.59 = 313.59/x
3. Step 3: Cross multiply
   143.30x = 313.59 × 313.59
4. Step 4: Simplify right side
   143.30x = 98,341.04
5. Step 5: Solve for x
   x = 98,341.04/143.30
6. Step 6: Final answer
   x = 686.27