Finding the Fourth Proportional to 1,665.05, 2,297.77 and 1,223.78

Step by Step Solution

1. Step 1: Write the proportion equation
   1,665.05 : 2,297.77 = 1,223.78 : x
2. Step 2: Convert to fraction form
   1,665.05/2,297.77 = 1,223.78/x
3. Step 3: Cross multiply
   1,665.05x = 2,297.77 × 1,223.78
4. Step 4: Simplify right side
   1,665.05x = 2,811,950.42
5. Step 5: Solve for x
   x = 2,811,950.42/1,665.05
6. Step 6: Final answer
   x = 1,688.81