Finding the Fourth Proportional to 19,153.16, 28,700.42 and 12,890

Step by Step Solution

1. Step 1: Write the proportion equation
   19,153.16 : 28,700.42 = 12,890 : x
2. Step 2: Convert to fraction form
   19,153.16/28,700.42 = 12,890/x
3. Step 3: Cross multiply
   19,153.16x = 28,700.42 × 12,890
4. Step 4: Simplify right side
   19,153.16x = 369,948,413.80
5. Step 5: Solve for x
   x = 369,948,413.80/19,153.16
6. Step 6: Final answer
   x = 19,315.27