Finding the Third Proportional to 818.81 and 1,216.78

Step by Step Solution

1. Step 1: Write the proportion equation
   818.81 : 1,216.78 = 1,216.78 : x
2. Step 2: Convert to fraction form
   818.81/1,216.78 = 1,216.78/x
3. Step 3: Cross multiply
   818.81x = 1,216.78 × 1,216.78
4. Step 4: Simplify right side
   818.81x = 1,480,556.61
5. Step 5: Solve for x
   x = 1,480,556.61/818.81
6. Step 6: Final answer
   x = 1,808.18