Finding the Fourth Proportional to 1,638.12, 2,261.42 and 1,116.89

Step by Step Solution

1. Step 1: Write the proportion equation
   1,638.12 : 2,261.42 = 1,116.89 : x
2. Step 2: Convert to fraction form
   1,638.12/2,261.42 = 1,116.89/x
3. Step 3: Cross multiply
   1,638.12x = 2,261.42 × 1,116.89
4. Step 4: Simplify right side
   1,638.12x = 2,525,740.49
5. Step 5: Solve for x
   x = 2,525,740.49/1,638.12
6. Step 6: Final answer
   x = 1,541.85