Finding the Fourth Proportional to 1,638.54, 2,456.73 and 868.86

Step by Step Solution

1. Step 1: Write the proportion equation
   1,638.54 : 2,456.73 = 868.86 : x
2. Step 2: Convert to fraction form
   1,638.54/2,456.73 = 868.86/x
3. Step 3: Cross multiply
   1,638.54x = 2,456.73 × 868.86
4. Step 4: Simplify right side
   1,638.54x = 2,134,554.43
5. Step 5: Solve for x
   x = 2,134,554.43/1,638.54
6. Step 6: Final answer
   x = 1,302.72