Finding the Fourth Proportional to 2,103.45, 3,155.69 and 642.53

Step by Step Solution

1. Step 1: Write the proportion equation
   2,103.45 : 3,155.69 = 642.53 : x
2. Step 2: Convert to fraction form
   2,103.45/3,155.69 = 642.53/x
3. Step 3: Cross multiply
   2,103.45x = 3,155.69 × 642.53
4. Step 4: Simplify right side
   2,103.45x = 2,027,606.50
5. Step 5: Solve for x
   x = 2,027,606.50/2,103.45
6. Step 6: Final answer
   x = 963.94