Finding the Third Proportional to 90.69 and 209.84

Step by Step Solution

1. Step 1: Write the proportion equation
   90.69 : 209.84 = 209.84 : x
2. Step 2: Convert to fraction form
   90.69/209.84 = 209.84/x
3. Step 3: Cross multiply
   90.69x = 209.84 × 209.84
4. Step 4: Simplify right side
   90.69x = 44,034.40
5. Step 5: Solve for x
   x = 44,034.40/90.69
6. Step 6: Final answer
   x = 485.56