Finding the Third Proportional to 840.38 and 1,222.31

Step by Step Solution

1. Step 1: Write the proportion equation
   840.38 : 1,222.31 = 1,222.31 : x
2. Step 2: Convert to fraction form
   840.38/1,222.31 = 1,222.31/x
3. Step 3: Cross multiply
   840.38x = 1,222.31 × 1,222.31
4. Step 4: Simplify right side
   840.38x = 1,494,047.85
5. Step 5: Solve for x
   x = 1,494,047.85/840.38
6. Step 6: Final answer
   x = 1,777.83