Finding the Third Proportional to 521.25 and 1,223

Step by Step Solution

1. Step 1: Write the proportion equation
   521.25 : 1,223 = 1,223 : x
2. Step 2: Convert to fraction form
   521.25/1,223 = 1,223/x
3. Step 3: Cross multiply
   521.25x = 1,223 × 1,223
4. Step 4: Simplify right side
   521.25x = 1,495,729
5. Step 5: Solve for x
   x = 1,495,729/521.25
6. Step 6: Final answer
   x = 2,869.50