Finding the Fourth Proportional to 21,120.71, 31,688.10 and 7,082.12

Step by Step Solution

1. Step 1: Write the proportion equation
   21,120.71 : 31,688.10 = 7,082.12 : x
2. Step 2: Convert to fraction form
   21,120.71/31,688.10 = 7,082.12/x
3. Step 3: Cross multiply
   21,120.71x = 31,688.10 × 7,082.12
4. Step 4: Simplify right side
   21,120.71x = 224,418,926.77
5. Step 5: Solve for x
   x = 224,418,926.77/21,120.71
6. Step 6: Final answer
   x = 10,625.54