Finding the Fourth Proportional to 21,128.33, 31,689.31 and 7,085.97

Step by Step Solution

1. Step 1: Write the proportion equation
   21,128.33 : 31,689.31 = 7,085.97 : x
2. Step 2: Convert to fraction form
   21,128.33/31,689.31 = 7,085.97/x
3. Step 3: Cross multiply
   21,128.33x = 31,689.31 × 7,085.97
4. Step 4: Simplify right side
   21,128.33x = 224,549,499.98
5. Step 5: Solve for x
   x = 224,549,499.98/21,128.33
6. Step 6: Final answer
   x = 10,627.89