Finding the Fourth Proportional to 21,123.45, 31,683.56 and 5,540.67

Step by Step Solution

1. Step 1: Write the proportion equation
   21,123.45 : 31,683.56 = 5,540.67 : x
2. Step 2: Convert to fraction form
   21,123.45/31,683.56 = 5,540.67/x
3. Step 3: Cross multiply
   21,123.45x = 31,683.56 × 5,540.67
4. Step 4: Simplify right side
   21,123.45x = 175,548,122.68
5. Step 5: Solve for x
   x = 175,548,122.68/21,123.45
6. Step 6: Final answer
   x = 8,310.58