Finding the Fourth Proportional to 2,309.62, 3,187.31 and 1,638.60

Step by Step Solution

1. Step 1: Write the proportion equation
   2,309.62 : 3,187.31 = 1,638.60 : x
2. Step 2: Convert to fraction form
   2,309.62/3,187.31 = 1,638.60/x
3. Step 3: Cross multiply
   2,309.62x = 3,187.31 × 1,638.60
4. Step 4: Simplify right side
   2,309.62x = 5,222,726.17
5. Step 5: Solve for x
   x = 5,222,726.17/2,309.62
6. Step 6: Final answer
   x = 2,261.29