Finding the Fourth Proportional to 9,571.78, 13,209.18 and 5,380

Step by Step Solution

1. Step 1: Write the proportion equation
   9,571.78 : 13,209.18 = 5,380 : x
2. Step 2: Convert to fraction form
   9,571.78/13,209.18 = 5,380/x
3. Step 3: Cross multiply
   9,571.78x = 13,209.18 × 5,380
4. Step 4: Simplify right side
   9,571.78x = 71,065,388.40
5. Step 5: Solve for x
   x = 71,065,388.40/9,571.78
6. Step 6: Final answer
   x = 7,424.47