Finding the Fourth Proportional to 21,751.12, 30,019.40 and 12,320

Step by Step Solution

1. Step 1: Write the proportion equation
   21,751.12 : 30,019.40 = 12,320 : x
2. Step 2: Convert to fraction form
   21,751.12/30,019.40 = 12,320/x
3. Step 3: Cross multiply
   21,751.12x = 30,019.40 × 12,320
4. Step 4: Simplify right side
   21,751.12x = 369,839,008
5. Step 5: Solve for x
   x = 369,839,008/21,751.12
6. Step 6: Final answer
   x = 17,003.22