Finding the Fourth Proportional to 2,171.78, 3,251.55 and 1,690.46

Step by Step Solution

1. Step 1: Write the proportion equation
   2,171.78 : 3,251.55 = 1,690.46 : x
2. Step 2: Convert to fraction form
   2,171.78/3,251.55 = 1,690.46/x
3. Step 3: Cross multiply
   2,171.78x = 3,251.55 × 1,690.46
4. Step 4: Simplify right side
   2,171.78x = 5,496,615.21
5. Step 5: Solve for x
   x = 5,496,615.21/2,171.78
6. Step 6: Final answer
   x = 2,530.93