Finding the Fourth Proportional to 18,978.15, 26,200.77 and 12,613.37

Step by Step Solution

1. Step 1: Write the proportion equation
   18,978.15 : 26,200.77 = 12,613.37 : x
2. Step 2: Convert to fraction form
   18,978.15/26,200.77 = 12,613.37/x
3. Step 3: Cross multiply
   18,978.15x = 26,200.77 × 12,613.37
4. Step 4: Simplify right side
   18,978.15x = 330,480,045.10
5. Step 5: Solve for x
   x = 330,480,045.10/18,978.15
6. Step 6: Final answer
   x = 17,413.72