Finding the Third Proportional to 813 and 1,225.50

Step by Step Solution

1. Step 1: Write the proportion equation
   813 : 1,225.50 = 1,225.50 : x
2. Step 2: Convert to fraction form
   813/1,225.50 = 1,225.50/x
3. Step 3: Cross multiply
   813x = 1,225.50 × 1,225.50
4. Step 4: Simplify right side
   813x = 1,501,850.25
5. Step 5: Solve for x
   x = 1,501,850.25/813
6. Step 6: Final answer
   x = 1,847.29