Finding the Fourth Proportional to 2,859.72, 3,945.70 and 1,680.56

Step by Step Solution

1. Step 1: Write the proportion equation
   2,859.72 : 3,945.70 = 1,680.56 : x
2. Step 2: Convert to fraction form
   2,859.72/3,945.70 = 1,680.56/x
3. Step 3: Cross multiply
   2,859.72x = 3,945.70 × 1,680.56
4. Step 4: Simplify right side
   2,859.72x = 6,630,985.59
5. Step 5: Solve for x
   x = 6,630,985.59/2,859.72
6. Step 6: Final answer
   x = 2,318.75