Finding the Fourth Proportional to 21,002.67, 31,494.65 and 11,139.71

Step by Step Solution

1. Step 1: Write the proportion equation
   21,002.67 : 31,494.65 = 11,139.71 : x
2. Step 2: Convert to fraction form
   21,002.67/31,494.65 = 11,139.71/x
3. Step 3: Cross multiply
   21,002.67x = 31,494.65 × 11,139.71
4. Step 4: Simplify right side
   21,002.67x = 350,841,054.38
5. Step 5: Solve for x
   x = 350,841,054.38/21,002.67
6. Step 6: Final answer
   x = 16,704.59