Finding the Fourth Proportional to 10,721.80, 16,085.25 and 4,478.35

Step by Step Solution

1. Step 1: Write the proportion equation
   10,721.80 : 16,085.25 = 4,478.35 : x
2. Step 2: Convert to fraction form
   10,721.80/16,085.25 = 4,478.35/x
3. Step 3: Cross multiply
   10,721.80x = 16,085.25 × 4,478.35
4. Step 4: Simplify right side
   10,721.80x = 72,035,379.34
5. Step 5: Solve for x
   x = 72,035,379.34/10,721.80
6. Step 6: Final answer
   x = 6,718.59