Finding the Fourth Proportional to 9,664.65, 13,361.59 and 7,142.78

Step by Step Solution

1. Step 1: Write the proportion equation
   9,664.65 : 13,361.59 = 7,142.78 : x
2. Step 2: Convert to fraction form
   9,664.65/13,361.59 = 7,142.78/x
3. Step 3: Cross multiply
   9,664.65x = 13,361.59 × 7,142.78
4. Step 4: Simplify right side
   9,664.65x = 95,438,940.15
5. Step 5: Solve for x
   x = 95,438,940.15/9,664.65
6. Step 6: Final answer
   x = 9,875.05