Finding the Fourth Proportional to 2,102.72, 3,154.25 and 641.89

Step by Step Solution

1. Step 1: Write the proportion equation
   2,102.72 : 3,154.25 = 641.89 : x
2. Step 2: Convert to fraction form
   2,102.72/3,154.25 = 641.89/x
3. Step 3: Cross multiply
   2,102.72x = 3,154.25 × 641.89
4. Step 4: Simplify right side
   2,102.72x = 2,024,662.55
5. Step 5: Solve for x
   x = 2,024,662.55/2,102.72
6. Step 6: Final answer
   x = 962.88