Finding the Third Proportional to 199.69 and 289.69

Step by Step Solution

1. Step 1: Write the proportion equation
   199.69 : 289.69 = 289.69 : x
2. Step 2: Convert to fraction form
   199.69/289.69 = 289.69/x
3. Step 3: Cross multiply
   199.69x = 289.69 × 289.69
4. Step 4: Simplify right side
   199.69x = 83,918.85
5. Step 5: Solve for x
   x = 83,918.85/199.69
6. Step 6: Final answer
   x = 420.25