Finding the Fourth Proportional to 21,123.25, 31,685.46 and 7,972.69

Step by Step Solution

1. Step 1: Write the proportion equation
   21,123.25 : 31,685.46 = 7,972.69 : x
2. Step 2: Convert to fraction form
   21,123.25/31,685.46 = 7,972.69/x
3. Step 3: Cross multiply
   21,123.25x = 31,685.46 × 7,972.69
4. Step 4: Simplify right side
   21,123.25x = 252,618,350.09
5. Step 5: Solve for x
   x = 252,618,350.09/21,123.25
6. Step 6: Final answer
   x = 11,959.26