Finding the Fourth Proportional to 10,665.16, 15,990.89 and 4,429.49

Step by Step Solution

1. Step 1: Write the proportion equation
   10,665.16 : 15,990.89 = 4,429.49 : x
2. Step 2: Convert to fraction form
   10,665.16/15,990.89 = 4,429.49/x
3. Step 3: Cross multiply
   10,665.16x = 15,990.89 × 4,429.49
4. Step 4: Simplify right side
   10,665.16x = 70,831,385.24
5. Step 5: Solve for x
   x = 70,831,385.24/10,665.16
6. Step 6: Final answer
   x = 6,641.38