CBSE NCERT Solution of Class 11 Informatics Practices
Chapter 5 – Understanding Data NCERT Exercise Solution
1. Identify data required to be maintained to perform the following services:
a) Declare exam results and print e-certificates
b) Register participants in an exhibition and issue biometric ID cards
c) To search for an image by a search engine
d) To book an OPD appointment with a hospital in a specific department.
Answer:
(a) Student details (name, class, marks, grade)
(b) Participants’ details (name, address, ID-proof)
(c) Image’s metadata (name, type, detail, size etc.)
(d) Appointment details (Doctor’s name, Dept, OPD slot, Patient’s name, Patient’s id, Patient’s contact number)
2. A school having 500 students wants to identify beneficiaries of the merit-cum means scholarship, achieving more than 75% for two consecutive years and having family income less than 5 lakh per annum. Briefly describe data processing steps to be taken by the to beneficial prepare the list of school.
Answer:
Input: Collect and Prepare student details which include :
Student details (admission numbers, name, class, marks) Family income details (admission Number, annual income)
Processing: Extract the student details with marks 2 75% and family income < 5 lakh per annum.
Output: List of beneficiaries
3. A bank ‘xyz’ wants to know about its popularity among the residents of a city ‘ABC’ on the basis of number of bank accounts each family has and the average monthly account balance of each person. Briefly describe the steps to be taken for collecting data and what results can be checked through processing of the collected data.
Answer: For collecting data, data from various branches of the Bank are accumulated. Once collected, data can be grouped on the basis of addresses and then a graph may be prepared which will give idea about Bank’s popularity among residents of a city.
4. Identify type of data being collected/generated in the following scenarios:
a) Recording a video
b) Marking attendance by teacher
c) Writing tweets
d) Filling an application form online
Answer: (a) Unstructured
(b) Structured
(c) Structured
(d) Structured
5. Consider the temperature (in Celsius) of 7 days of a week as 34, 34, 27, 28, 27, 34, 34. Identify the appropriate statistical technique to be used to calculate the following:
a) Find the average temperature.
b) Find the temperature Range of that week.
c) Find the standard deviation temperature.
Answer:
(a) Mean
(b) Range,
(c) Standard deviation
6. A school teacher wants to analyse results. Identify the appropriate statistical technique to be used along with its justification for the following cases:
a) Teacher wants to compare performance in terms of division secured by students in Class XII A and Class XII B where each class strength is same.
b) Teacher has conducted five unit tests for that class in months July to November and wants to compare the class performance in these five months.
Answer:
(a) Mean
(b) Mean and Median
7. Suppose annual day of your school is to be celebrated. The school has decided to felicitate those parents of the students studying in classes XI and XII, who are the alumni of the same school. In this context, answer the following questions:
a) Which statistical technique should be used to find out the number of students whose both parents are alumni of this school?
b) How varied are the age of parents of the students of that school?
Answer:
(a) Mode
(b) Range or Standard deviation
For the annual day celebrations, the teacher is looking for an anchor in a class of 42 students. The teacher would make selection of an anchor on the basis of singing skill, writing skill, as well as monitoring skill.
a) Which mode of data collection should be used?
b) How would you represent the skill of students as data?
9. Differentiate between structured and unstructured data giving one example.
10. The principal of a school wants to do following analysis on the basis of food items procured and sold in the canteen:
a) Compare the purchase and sale price of fruit juice and biscuits.
b) Compare sales of fruit juice, biscuits and samosa.
c) Variation in sale price of fruit juices of different companies for same quantity (in ml).
Create an appropriate dataset for these items (fruit juice, biscuits, samosa) by listing their purchase price and sale price. Apply basic statistical techniques to make the comparisons.
Answer:
(a) Range and Mean
(b) Mean
(c) Standard deviation
