Finding the Fourth Proportional to 21,050.71, 31,520.14 and 12,719.45

Step by Step Solution

1. Step 1: Write the proportion equation
   21,050.71 : 31,520.14 = 12,719.45 : x
2. Step 2: Convert to fraction form
   21,050.71/31,520.14 = 12,719.45/x
3. Step 3: Cross multiply
   21,050.71x = 31,520.14 × 12,719.45
4. Step 4: Simplify right side
   21,050.71x = 400,918,891.72
5. Step 5: Solve for x
   x = 400,918,891.72/21,050.71
6. Step 6: Final answer
   x = 19,045.39