Finding the Fourth Proportional to 21,574.78, 29,768.76 and 12,620.50

Step by Step Solution

1. Step 1: Write the proportion equation
   21,574.78 : 29,768.76 = 12,620.50 : x
2. Step 2: Convert to fraction form
   21,574.78/29,768.76 = 12,620.50/x
3. Step 3: Cross multiply
   21,574.78x = 29,768.76 × 12,620.50
4. Step 4: Simplify right side
   21,574.78x = 375,696,635.58
5. Step 5: Solve for x
   x = 375,696,635.58/21,574.78
6. Step 6: Final answer
   x = 17,413.69