Finding the Fourth Proportional to 9,840.50, 13,579.89 and 5,424.50

Step by Step Solution

1. Step 1: Write the proportion equation
   9,840.50 : 13,579.89 = 5,424.50 : x
2. Step 2: Convert to fraction form
   9,840.50/13,579.89 = 5,424.50/x
3. Step 3: Cross multiply
   9,840.50x = 13,579.89 × 5,424.50
4. Step 4: Simplify right side
   9,840.50x = 73,664,113.31
5. Step 5: Solve for x
   x = 73,664,113.31/9,840.50
6. Step 6: Final answer
   x = 7,485.81