Finding the Fourth Proportional to 10,721.89, 16,085.40 and 4,478.46

Step by Step Solution

1. Step 1: Write the proportion equation
   10,721.89 : 16,085.40 = 4,478.46 : x
2. Step 2: Convert to fraction form
   10,721.89/16,085.40 = 4,478.46/x
3. Step 3: Cross multiply
   10,721.89x = 16,085.40 × 4,478.46
4. Step 4: Simplify right side
   10,721.89x = 72,037,820.48
5. Step 5: Solve for x
   x = 72,037,820.48/10,721.89
6. Step 6: Final answer
   x = 6,718.76