Organize the following marks in a class assessment, in a tabular form.

4,6,7,5,3,5,4,5,2,6,2,5,1,9,6,5,8,4,6,7


(i) Which number is the highest?


(ii) Which number is the lowest?


(iii) What is the range of the data?


(iv) Find the arithmetic mean.

According to the question,


At first,


We will draw the frequency table of the given data.


Hence,



Marks



Tally marks



Frequency



1



I



1



2



II



2



3



I



1



4



III



3



5



IIII



5



6



IIII



4



7



II



2



8



I



1



9



I



1




(i) Now,


Clearly, The highest number among the given data is 9


(ii) Clearly, The lowest number among the given data is 1


(iii)


We know that,


Range = Highest value – Lowest value


Hence,


Range of the given data can be calculated as follows:


Range = highest number – lowest number


= 9 – 1


= 8


(iv) Here,


We have to find the arithmetic mean of the given data


Now,


At first,


We’ll find the sum of all the observations


Thus,


Sum of all the observations = 4 + 6 + 7 + 5 + 3 + 5 + 4 + 5 + 2 + 6 + 2 + 5 + 1 + 9 + 6 + 5 + 8 + 4 + 6 + 7 = 100


Now,


Total number of observations = 20


Hence,


Arithmetic mean =


=


= 5


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