Finding the Fourth Proportional to 3,638.62, 5,021.34 and 2,221.72

Step by Step Solution

1. Step 1: Write the proportion equation
   3,638.62 : 5,021.34 = 2,221.72 : x
2. Step 2: Convert to fraction form
   3,638.62/5,021.34 = 2,221.72/x
3. Step 3: Cross multiply
   3,638.62x = 5,021.34 × 2,221.72
4. Step 4: Simplify right side
   3,638.62x = 11,156,011.50
5. Step 5: Solve for x
   x = 11,156,011.50/3,638.62
6. Step 6: Final answer
   x = 3,066.00