Which of the following are primaryt and secondary data ?
(i) Collection of the data about enrollment of students in your school for a period from 2001 to 2010.
(ii) Height of students in your class recorded by physical education teacher.

Which of the following are sets? Justify your answer (i) The collection of all the months of a year begimng with the letter "J". (ii) The collection of ten most talented writers of India. (iii) A team of eleven best cricket batsmen of the world. (iv) The collectionofall boys in your class. (v) The collection of all even integers.

The following table gives the information about the number of students in different standards of a school : Represent the data by a Bar graph.

To suggest rule for inheritance of earlobe type. Procedure /Method : rarr The lowest part of the ear pinna called the earlobe, is closely attached to the side of the head, i.e., attached or not, i.e., free. rarr Observe the earlobes of all the students in the class. Prepare a list of students. Enter the data about the earlobes whether they are free or attached. rarr Find out about the earlobes of the parents of each student in the class. rarr Correlate earlobe type of each student with that of their parents. rarr In the column write F for free earlobe and A for attached earlobe. Answer the following questions on the basis of the collected data: From your collected data state which expression is dominant and which one is recessive for earlobe.

To suggest rule for inheritance of earlobe type. Procedure /Method : rarr The lowest part of the ear pinna called the earlobe, is closely attached to the side of the head, i.e., attached or not, i.e., free. rarr Observe the earlobes of all the students in the class. Prepare a list of students. Enter the data about the earlobes whether they are free or attached. rarr Find out about the earlobes of the parents of each student in the class. rarr Correlate earlobe type of each student with that of their parents. rarr In the column write F for free earlobe and A for attached earlobe. Answer the following questions on the basis of the collected data: Which expression of earlobe is observed more in number in your class?

There are 40 students in Class X of a school of whom 25 are girls and 15 are boys. The class teacher has to select one student as a class representative. She writes the name of each student on separate cards, the cards being identical. Then she puts cards in a box and stirs them thoroughly. She then draws one card from the box. What is the probability that the name written on the card is the name of (i) a girl? (ii) a boy?

The heights of 50 students, measured to the nearest centimetres, have been found to be as follows: (i) Represent the data given above by a grouped frequency distribution table, taking the class intervals as 160 - 165,165-170, etc. (ii) What can you conclude about their heights from the table ?

In a particular section of Class IX, 40 students were asked about the month of their birth and the following graph was prepared for the data so obtained : Observe the bar graph given above and answer the following questions: ( i ) How many students were born in the month of November? (ii) in which month were the maximum number of students born ?