Finding the Fourth Proportional to 9,405.94, 12,980.36 and 5,157.42

Step by Step Solution

1. Step 1: Write the proportion equation
   9,405.94 : 12,980.36 = 5,157.42 : x
2. Step 2: Convert to fraction form
   9,405.94/12,980.36 = 5,157.42/x
3. Step 3: Cross multiply
   9,405.94x = 12,980.36 × 5,157.42
4. Step 4: Simplify right side
   9,405.94x = 66,945,168.27
5. Step 5: Solve for x
   x = 66,945,168.27/9,405.94
6. Step 6: Final answer
   x = 7,117.33