A boy scored the following marks in various class tests during a term, each test being marked out of 20.

15, 17, 16, 7, 10, 12, 14, 16, 19, 12 and 16.

(i) What are his modal marks ?

(ii) What are his median marks ?

(iii) What are his total marks ?

(iv) What are his mean marks ?

(i) From above data,

16 occurs for the maximum time.

Hence, mode = 16.

(ii) Arranging the numbers in ascending order :

7, 10, 12, 12, 14, 15, 16, 16, 16, 17, 19.

Here, n = 11, which is odd.

By formula,

Median = $\dfrac{n + 1}{2}$ th term

= $\dfrac{11 + 1}{2} = \dfrac{12}{2}$

= 6th term

= 15.

Hence, median = 15.

(iii) Total marks = 7 + 10 + 12 + 12 + 14 + 15 + 16 + 16 + 16 + 17 + 19

= 154.

Hence, total marks = 154.

(iv) Mean = $\dfrac{\text{Total marks}}{\text{No. of tests}}$

= $\dfrac{154}{11}$

= 14.

Hence, mean = 14.