Finding the Third Proportional to 777 and 1,222.50

Step by Step Solution

1. Step 1: Write the proportion equation
   777 : 1,222.50 = 1,222.50 : x
2. Step 2: Convert to fraction form
   777/1,222.50 = 1,222.50/x
3. Step 3: Cross multiply
   777x = 1,222.50 × 1,222.50
4. Step 4: Simplify right side
   777x = 1,494,506.25
5. Step 5: Solve for x
   x = 1,494,506.25/777
6. Step 6: Final answer
   x = 1,923.43