Finding the Fourth Proportional to 1,638.78, 2,455.61 and 1,029.50

Step by Step Solution

1. Step 1: Write the proportion equation
   1,638.78 : 2,455.61 = 1,029.50 : x
2. Step 2: Convert to fraction form
   1,638.78/2,455.61 = 1,029.50/x
3. Step 3: Cross multiply
   1,638.78x = 2,455.61 × 1,029.50
4. Step 4: Simplify right side
   1,638.78x = 2,528,050.50
5. Step 5: Solve for x
   x = 2,528,050.50/1,638.78
6. Step 6: Final answer
   x = 1,542.64