Finding the Fourth Proportional to 2,103.47, 3,155.25 and 642.74

Step by Step Solution

1. Step 1: Write the proportion equation
   2,103.47 : 3,155.25 = 642.74 : x
2. Step 2: Convert to fraction form
   2,103.47/3,155.25 = 642.74/x
3. Step 3: Cross multiply
   2,103.47x = 3,155.25 × 642.74
4. Step 4: Simplify right side
   2,103.47x = 2,027,992.02
5. Step 5: Solve for x
   x = 2,027,992.02/2,103.47
6. Step 6: Final answer
   x = 964.12