Page 153 - Data Science class 10
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7 No Yes Yes No 19 Yes Yes Yes Yes
8 Yes Yes Yes Yes 20 Yes Yes Yes Yes
9 Yes Yes Yes Yes 21 Yes Yes Yes No
10 Yes Yes Yes Yes 22 No Yes Yes Yes
11 Yes Yes Yes Yes 23 Yes Yes Yes Yes
12 No Yes Yes No 24 No Yes Yes Yes
25 No Yes Yes No
a. For Questions 1, 3, and 4, there are differences in the 25 responses to each question. What are the sources of
this variation?
b. For Question 2, there was no variation. Why? Would you expect the same results from another sample of 25
people?
c. Take a closer look at this questionnaire. How are the questions posed, and how might that influence
responses?
2.4. ACTIVITY - CHOOSING GROUPS FOR SCHOOL DANCE PROGRAMS
Consider that there is an annual event in your school for which you all are planning to shortlist a musical group for
a single grade. You can do this by conducting a class census. Let us ask following statistical question to go start
with the activity:
What type of music do the students in our grade like?
To start with, we can start collecting data for each class. We will collect data for entire population of the class, i.e.,
each student will answer this question. Later, we will extend the collection to the entire grade.
On similar grounds, we may also plan to collect data for the entire school. This is because one single class may not
represent the preferences of all students in one grade or all students at the school.
Now that we have all the data with us, each class can compare preferences of their class with the preferences of
other classes of the school and explore the following statistical question:
What type of music do the students at our school like?
2.4.1. Collect/Consider Data
The statistical question 'What type of music do the students at our school like?' asks about the preferences of
students at the school overall. In this case, a data collection plan may use a single class, for example, grade 10
English class, as a sample to make decisions for the whole school. In this situation, we can discuss the limitations
of the chosen sample. Alternatively, what we can do is that we can randomly select few students from each class
or select couple of classes and get all the students in those classes to complete a survey.
To excel further, we can improve on survey questions used before by understanding potential pitfalls to avoid in
survey design (like ambiguous wording and misleading questions) or maybe by providing more choices in the
answers. Additionally, we can collect the data on multiple aspects of the topic which can foreshadow answering
the other statistical investigative questions.
For example, we can pose a series of survey questions that allow us to explore in more depth the types of music
which students like. After collecting all the data, we can look at whether an association appears to be likely
between different types of music which students like. This information might tell us the choice of music for the
school dance.
Distributions in Data Science 151

