Finding the Fourth Proportional to 2,648.55, 3,972.91 and 1,005.21

Step by Step Solution

1. Step 1: Write the proportion equation
   2,648.55 : 3,972.91 = 1,005.21 : x
2. Step 2: Convert to fraction form
   2,648.55/3,972.91 = 1,005.21/x
3. Step 3: Cross multiply
   2,648.55x = 3,972.91 × 1,005.21
4. Step 4: Simplify right side
   2,648.55x = 3,993,608.86
5. Step 5: Solve for x
   x = 3,993,608.86/2,648.55
6. Step 6: Final answer
   x = 1,507.85