Concept:
Mode is the value that occurs most frequently in a data set.
It is one of the important measures of central tendency.
A data set may have:
• One mode \(\rightarrow\) Unimodal
• Two modes \(\rightarrow\) Bimodal
• More than two modes \(\rightarrow\) Multimodal
To find the mode:
• Count the frequency of each observation
• Identify the observation with the highest frequency
Step 1: Writing the given observations carefully.
The given data is:
\[
5,\ 7,\ 9,\ 7,\ 11,\ 13,\ 7,\ 15,\ 17,\ 19
\]
Step 2: Counting the frequency of each observation.
Let us count how many times each number appears.
• \(5\) appears \(1\) time
• \(7\) appears \(3\) times
• \(9\) appears \(1\) time
• \(11\) appears \(1\) time
• \(13\) appears \(1\) time
• \(15\) appears \(1\) time
• \(17\) appears \(1\) time
• \(19\) appears \(1\) time
Step 3: Identifying the observation with maximum frequency.
From the frequency count:
\[
7
\]
appears \(3\) times.
All other numbers appear only once.
Therefore, the number with the highest frequency is:
\[
7
\]
Hence:
\[
\text{Mode}=7
\]
Step 4: Checking the options carefully.
Option (1):
\[
5
\]
Incorrect.
Option (2):
\[
7
\]
Correct.
Option (3):
\[
11
\]
Incorrect.
Option (4):
\[
15
\]
Incorrect.
Final Conclusion:
The mode of the given data is:
\[
\boxed{7}
\]
Hence, the correct answer is option (2).