Finding the Fourth Proportional to 9,405.78, 12,979.16 and 5,372.59

Step by Step Solution

1. Step 1: Write the proportion equation
   9,405.78 : 12,979.16 = 5,372.59 : x
2. Step 2: Convert to fraction form
   9,405.78/12,979.16 = 5,372.59/x
3. Step 3: Cross multiply
   9,405.78x = 12,979.16 × 5,372.59
4. Step 4: Simplify right side
   9,405.78x = 69,731,613.47
5. Step 5: Solve for x
   x = 69,731,613.47/9,405.78
6. Step 6: Final answer
   x = 7,413.70