Finding the Fourth Proportional to 1,638.02, 2,260.31 and 1,008.45

Step by Step Solution

1. Step 1: Write the proportion equation
   1,638.02 : 2,260.31 = 1,008.45 : x
2. Step 2: Convert to fraction form
   1,638.02/2,260.31 = 1,008.45/x
3. Step 3: Cross multiply
   1,638.02x = 2,260.31 × 1,008.45
4. Step 4: Simplify right side
   1,638.02x = 2,279,404.58
5. Step 5: Solve for x
   x = 2,279,404.58/1,638.02
6. Step 6: Final answer
   x = 1,391.56