Finding the Fourth Proportional to 21,061.44, 31,603.59 and 7,912.80

Step by Step Solution

1. Step 1: Write the proportion equation
   21,061.44 : 31,603.59 = 7,912.80 : x
2. Step 2: Convert to fraction form
   21,061.44/31,603.59 = 7,912.80/x
3. Step 3: Cross multiply
   21,061.44x = 31,603.59 × 7,912.80
4. Step 4: Simplify right side
   21,061.44x = 250,072,886.95
5. Step 5: Solve for x
   x = 250,072,886.95/21,061.44
6. Step 6: Final answer
   x = 11,873.49