Finding the Fourth Proportional to 9,619.72, 13,271.49 and 5,639.38

Step by Step Solution

1. Step 1: Write the proportion equation
   9,619.72 : 13,271.49 = 5,639.38 : x
2. Step 2: Convert to fraction form
   9,619.72/13,271.49 = 5,639.38/x
3. Step 3: Cross multiply
   9,619.72x = 13,271.49 × 5,639.38
4. Step 4: Simplify right side
   9,619.72x = 74,842,975.28
5. Step 5: Solve for x
   x = 74,842,975.28/9,619.72
6. Step 6: Final answer
   x = 7,780.16