Finding the Fourth Proportional to 21,211, 31,811.24 and 7,170.72

Step by Step Solution

1. Step 1: Write the proportion equation
   21,211 : 31,811.24 = 7,170.72 : x
2. Step 2: Convert to fraction form
   21,211/31,811.24 = 7,170.72/x
3. Step 3: Cross multiply
   21,211x = 31,811.24 × 7,170.72
4. Step 4: Simplify right side
   21,211x = 228,109,494.89
5. Step 5: Solve for x
   x = 228,109,494.89/21,211
6. Step 6: Final answer
   x = 10,754.30