Finding the Fourth Proportional to 21,167.89, 31,752.28 and 7,128.34

Step by Step Solution

1. Step 1: Write the proportion equation
   21,167.89 : 31,752.28 = 7,128.34 : x
2. Step 2: Convert to fraction form
   21,167.89/31,752.28 = 7,128.34/x
3. Step 3: Cross multiply
   21,167.89x = 31,752.28 × 7,128.34
4. Step 4: Simplify right side
   21,167.89x = 226,340,888.85
5. Step 5: Solve for x
   x = 226,340,888.85/21,167.89
6. Step 6: Final answer
   x = 10,692.65