Question

Kavita obtained 16, 14, 18 and 20 marks (out of 25) in Maths in weekly tests in the month of Jan 2000; then mean marks of Kavita is:
A. 16
B. 16.5
C. 17
D. 17.5

Answer 1

Hint: We will first note down the formula of mean marks. After that, we will evaluate the sum of all the marks obtained by her which need to be filled in the formula to get the required answer.

Complete step-by-step solution:
Since, we are given that Kavita has obtained 16, 14, 18 and 20 marks (out of 25) in Maths in weekly tests in the month of January 2000.
We need to find the mean marks which can also be called as the average marks of Kavita.
We will use the formula given by the following expression:-
$ \Rightarrow $ Mean is given by the division of sum of observations by the number of observations.
This can be written as the following expression:-
$ \Rightarrow Mean = \dfrac{S}{n}$, where S represents the sum of the observations and n represents the number of observations.
Now, let us find the value of S as per the given that.
$ \Rightarrow $ S = Sum of all the marks obtained by Kavita in weekly tests of Maths = 16 + 14 + 18 + 20 = 68
Now, since these were 4 tests, therefore n = 4.
Now, putting these values in the formula stated above, we will obtain:-
$ \Rightarrow Mean = \dfrac{{68}}{4}$
We can write the numerator on the right hand side as the following:-
$ \Rightarrow Mean = \dfrac{{4 \times 17}}{4}$
Simplifying the calculations on the right hand side, we will then obtain:-
$ \Rightarrow $ Mean = 17
$\therefore $ The correct option is (C).

Note: The students must commit to the memory the following formula:-
$ \Rightarrow Mean = \dfrac{S}{n}$, where S represents the sum of the observations and n represents the number of observations.
The students must also note that Mean basically represents the mid value of the data. Like in the above question, we can only refer to the mean marks that is 17 out of 25 to get an idea about how Kavita is doing in her tests.