Finding the Fourth Proportional to 2,120.73, 3,168.15 and 1,688.37

Step by Step Solution

1. Step 1: Write the proportion equation
   2,120.73 : 3,168.15 = 1,688.37 : x
2. Step 2: Convert to fraction form
   2,120.73/3,168.15 = 1,688.37/x
3. Step 3: Cross multiply
   2,120.73x = 3,168.15 × 1,688.37
4. Step 4: Simplify right side
   2,120.73x = 5,349,009.42
5. Step 5: Solve for x
   x = 5,349,009.42/2,120.73
6. Step 6: Final answer
   x = 2,522.25