Finding the Third Proportional to 314.86 and 489.59

Step by Step Solution

1. Step 1: Write the proportion equation
   314.86 : 489.59 = 489.59 : x
2. Step 2: Convert to fraction form
   314.86/489.59 = 489.59/x
3. Step 3: Cross multiply
   314.86x = 489.59 × 489.59
4. Step 4: Simplify right side
   314.86x = 239,694.39
5. Step 5: Solve for x
   x = 239,694.39/314.86
6. Step 6: Final answer
   x = 761.27