Finding the Third Proportional to 121.50 and 145.69

Step by Step Solution

1. Step 1: Write the proportion equation
   121.50 : 145.69 = 145.69 : x
2. Step 2: Convert to fraction form
   121.50/145.69 = 145.69/x
3. Step 3: Cross multiply
   121.50x = 145.69 × 145.69
4. Step 4: Simplify right side
   121.50x = 21,224.85
5. Step 5: Solve for x
   x = 21,224.85/121.50
6. Step 6: Final answer
   x = 174.69