Finding the Fourth Proportional to 20,976.42, 31,457.61 and 7,122.18

Step by Step Solution

1. Step 1: Write the proportion equation
   20,976.42 : 31,457.61 = 7,122.18 : x
2. Step 2: Convert to fraction form
   20,976.42/31,457.61 = 7,122.18/x
3. Step 3: Cross multiply
   20,976.42x = 31,457.61 × 7,122.18
4. Step 4: Simplify right side
   20,976.42x = 224,046,760.79
5. Step 5: Solve for x
   x = 224,046,760.79/20,976.42
6. Step 6: Final answer
   x = 10,680.89