Mathematics
Define the following terms:
(i) Variable
(ii) Class-interval
(iii) Class-size
(iv) Class-mark
(v) Class-limits
(vi) True class-limits
(Vii) Frequency of a class
(viii) Cumulative frequency of a class
Answer
(i) Variable : A quantity which can take different values is called a variable.
(ii) Class-interval : A range of values into which data is grouped in a frequency distribution.
(iii) Class-size : It is the difference between the true upper limit and the true lower limit of class.
(iv) Class-mark : It is the midpoint( middle value) of a class-interval.
(v) Class-limits : These are the smallest and largest values of the class interval.
(vi) True class-limits : These are the actual limits of a class interval after removing the gap between two consecutive classes.
(vii) Frequency of a class : It is the number of observations that fall within that class-interval.
(viii) Cumulative frequency of a class : It is the sum of the frequencies of all the previous classes and that particular class.
Related Questions
The class marks of a frequency distribution are 28, 34, 40, 46, 52. Find the class-size and all the class intervals.
State which of the following variables are continuous and which are discrete :
(i) Marks obtained by the students of a class in a test.
(ii) Daily maximum temperature of a city.
(iii) I.Q. of a students of a class.
(iv) Weights of players of a Volley-ball team.
(v) Number of car-accidents in a city.
(vi) Distance travelled by a train.
(vii) Time taken by runners in a race.
(viii) Sizes of shoes sold in a shoe-store.
(ix) Number of patients in a hospital per day.
Following data gives the number of children in 40 families :
1, 2, 6, 5, 1, 3, 2, 6, 2, 3, 4, 2, 0, 4, 4, 3, 2, 2, 0, 0, 1, 2, 2, 4, 4, 3, 2, 1, 0, 5, 1, 2, 4, 3, 4, 1, 1, 6, 2, 2
Represent it in the form of a frequency distribution.
The marks obtained by 40 students of a class in an examination are given below. Present the data in the form of a frequency distribution using equal class-size, one such class being 10 - 15(15 not included).
3, 20, 13, 1, 21, 13, 3, 23, 16, 13, 18, 12, 5, 12, 5, 24, 9, 2, 7, 18, 20, 3, 10, 12, 7, 18, 2, 5, 7, 10, 16, 8, 16, 17, 8, 23, 21, 6, 23, 15