Finding the Fourth Proportional to 1,636.89, 2,257.17 and 1,216.55

Step by Step Solution

1. Step 1: Write the proportion equation
   1,636.89 : 2,257.17 = 1,216.55 : x
2. Step 2: Convert to fraction form
   1,636.89/2,257.17 = 1,216.55/x
3. Step 3: Cross multiply
   1,636.89x = 2,257.17 × 1,216.55
4. Step 4: Simplify right side
   1,636.89x = 2,745,961.24
5. Step 5: Solve for x
   x = 2,745,961.24/1,636.89
6. Step 6: Final answer
   x = 1,677.55