Finding the Third Proportional to 143.86 and 314.30

Step by Step Solution

1. Step 1: Write the proportion equation
   143.86 : 314.30 = 314.30 : x
2. Step 2: Convert to fraction form
   143.86/314.30 = 314.30/x
3. Step 3: Cross multiply
   143.86x = 314.30 × 314.30
4. Step 4: Simplify right side
   143.86x = 98,782.53
5. Step 5: Solve for x
   x = 98,782.53/143.86
6. Step 6: Final answer
   x = 686.66