Finding the Fourth Proportional to 10,355.21, 14,290.35 and 5,639.49

Step by Step Solution

1. Step 1: Write the proportion equation
   10,355.21 : 14,290.35 = 5,639.49 : x
2. Step 2: Convert to fraction form
   10,355.21/14,290.35 = 5,639.49/x
3. Step 3: Cross multiply
   10,355.21x = 14,290.35 × 5,639.49
4. Step 4: Simplify right side
   10,355.21x = 80,590,264.77
5. Step 5: Solve for x
   x = 80,590,264.77/10,355.21
6. Step 6: Final answer
   x = 7,782.58