Finding the Third Proportional to 143.81 and 310.69

Step by Step Solution

1. Step 1: Write the proportion equation
   143.81 : 310.69 = 310.69 : x
2. Step 2: Convert to fraction form
   143.81/310.69 = 310.69/x
3. Step 3: Cross multiply
   143.81x = 310.69 × 310.69
4. Step 4: Simplify right side
   143.81x = 96,526.72
5. Step 5: Solve for x
   x = 96,526.72/143.81
6. Step 6: Final answer
   x = 671.20