Step 1: Arrange the data in ascending order.
Given data:
\[
15,\;8,\;10,\;6,\;11,\;9,\;15,\;7,\;14,\;5,\;17,\;14,\;8,\;14,\;12
\]
Arranging in ascending order:
\[
5,\;6,\;7,\;8,\;8,\;9,\;10,\;11,\;12,\;14,\;14,\;14,\;15,\;15,\;17
\]
Step 2: Count the number of observations.
Total number of observations is
\[
n=15
\]
Since \(n\) is odd, median is the middle term.
Step 3: Find the median position.
Median position is given by
\[
\frac{n+1}{2}
=
\frac{15+1}{2}
=
8
\]
So, the median is the \(8^{th}\) term.
Step 4: Determine the median.
The \(8^{th}\) term in the ordered data is
\[
11
\]
Therefore,
\[
\text{Median}=11
\]
Hence, option (A) is correct and option (C) is incorrect.
Step 5: Find the mode.
Mode is the observation that occurs most frequently.
From the ordered data:
\[
14 \text{ occurs } 3 \text{ times}
\]
\[
15 \text{ occurs } 2 \text{ times}
\]
\[
8 \text{ occurs } 2 \text{ times}
\]
All other values occur once.
Step 6: Determine the mode.
Since \(14\) occurs the maximum number of times,
\[
\text{Mode}=14
\]
Hence, option (D) is correct and option (B) is incorrect.
Step 7: Final conclusion.
Thus, the correct statements are
\[
\boxed{\text{(A) and (D)}}
\]