Finding the Fourth Proportional to 1,688.43, 2,327.79 and 1,290.33

Step by Step Solution

1. Step 1: Write the proportion equation
   1,688.43 : 2,327.79 = 1,290.33 : x
2. Step 2: Convert to fraction form
   1,688.43/2,327.79 = 1,290.33/x
3. Step 3: Cross multiply
   1,688.43x = 2,327.79 × 1,290.33
4. Step 4: Simplify right side
   1,688.43x = 3,003,614.85
5. Step 5: Solve for x
   x = 3,003,614.85/1,688.43
6. Step 6: Final answer
   x = 1,778.94