Finding the Fourth Proportional to 9,639.39, 13,302.63 and 5,390.34

Step by Step Solution

1. Step 1: Write the proportion equation
   9,639.39 : 13,302.63 = 5,390.34 : x
2. Step 2: Convert to fraction form
   9,639.39/13,302.63 = 5,390.34/x
3. Step 3: Cross multiply
   9,639.39x = 13,302.63 × 5,390.34
4. Step 4: Simplify right side
   9,639.39x = 71,705,698.59
5. Step 5: Solve for x
   x = 71,705,698.59/9,639.39
6. Step 6: Final answer
   x = 7,438.82