Finding the Fourth Proportional to 10,419.68, 14,379.18 and 5,639.63

Step by Step Solution

1. Step 1: Write the proportion equation
   10,419.68 : 14,379.18 = 5,639.63 : x
2. Step 2: Convert to fraction form
   10,419.68/14,379.18 = 5,639.63/x
3. Step 3: Cross multiply
   10,419.68x = 14,379.18 × 5,639.63
4. Step 4: Simplify right side
   10,419.68x = 81,093,154.81
5. Step 5: Solve for x
   x = 81,093,154.81/10,419.68
6. Step 6: Final answer
   x = 7,782.69