Finding the Fourth Proportional to 21,888, 30,213.12 and 13,056

Step by Step Solution

1. Step 1: Write the proportion equation
   21,888 : 30,213.12 = 13,056 : x
2. Step 2: Convert to fraction form
   21,888/30,213.12 = 13,056/x
3. Step 3: Cross multiply
   21,888x = 30,213.12 × 13,056
4. Step 4: Simplify right side
   21,888x = 394,462,494.72
5. Step 5: Solve for x
   x = 394,462,494.72/21,888
6. Step 6: Final answer
   x = 18,021.86