Finding the Fourth Proportional to 2,108.82, 3,163.38 and 647.78

Step by Step Solution

1. Step 1: Write the proportion equation
   2,108.82 : 3,163.38 = 647.78 : x
2. Step 2: Convert to fraction form
   2,108.82/3,163.38 = 647.78/x
3. Step 3: Cross multiply
   2,108.82x = 3,163.38 × 647.78
4. Step 4: Simplify right side
   2,108.82x = 2,049,174.30
5. Step 5: Solve for x
   x = 2,049,174.30/2,108.82
6. Step 6: Final answer
   x = 971.72