Finding the Fourth Proportional to 20,969.50, 31,459.12 and 7,118.50

Step by Step Solution

1. Step 1: Write the proportion equation
   20,969.50 : 31,459.12 = 7,118.50 : x
2. Step 2: Convert to fraction form
   20,969.50/31,459.12 = 7,118.50/x
3. Step 3: Cross multiply
   20,969.50x = 31,459.12 × 7,118.50
4. Step 4: Simplify right side
   20,969.50x = 223,941,745.72
5. Step 5: Solve for x
   x = 223,941,745.72/20,969.50
6. Step 6: Final answer
   x = 10,679.40