Finding the Fourth Proportional to 2,104.02, 3,155.91 and 643.05

Step by Step Solution

1. Step 1: Write the proportion equation
   2,104.02 : 3,155.91 = 643.05 : x
2. Step 2: Convert to fraction form
   2,104.02/3,155.91 = 643.05/x
3. Step 3: Cross multiply
   2,104.02x = 3,155.91 × 643.05
4. Step 4: Simplify right side
   2,104.02x = 2,029,419.76
5. Step 5: Solve for x
   x = 2,029,419.76/2,104.02
6. Step 6: Final answer
   x = 964.55