Finding the Fourth Proportional to 2,103.39, 3,154.55 and 642.51

Step by Step Solution

1. Step 1: Write the proportion equation
   2,103.39 : 3,154.55 = 642.51 : x
2. Step 2: Convert to fraction form
   2,103.39/3,154.55 = 642.51/x
3. Step 3: Cross multiply
   2,103.39x = 3,154.55 × 642.51
4. Step 4: Simplify right side
   2,103.39x = 2,026,826.71
5. Step 5: Solve for x
   x = 2,026,826.71/2,103.39
6. Step 6: Final answer
   x = 963.60