Finding the Fourth Proportional to 21,118.50, 31,684.71 and 7,085.13

Step by Step Solution

1. Step 1: Write the proportion equation
   21,118.50 : 31,684.71 = 7,085.13 : x
2. Step 2: Convert to fraction form
   21,118.50/31,684.71 = 7,085.13/x
3. Step 3: Cross multiply
   21,118.50x = 31,684.71 × 7,085.13
4. Step 4: Simplify right side
   21,118.50x = 224,490,289.36
5. Step 5: Solve for x
   x = 224,490,289.36/21,118.50
6. Step 6: Final answer
   x = 10,630.03