Question

(a) none of these
19. CASE STUDY BASED-3
A class teacher has the following record of marks obtained by 50 students of his class.
0-
Marks
obtained
20-
40
40-
60
60-
80
80-
100
20
3
5
12
20
No. Of
students
10
a) Estimate the mean marks obtained by a student(i) 39.7
(ii) 47.6 (ili) 79.3. iv) 29.6
b) If d; is the deviation of x; from assumed mean a. If mean is
Rotation or Turn
Ef
Efidi
then x is: (i) number of observations (li) assumed mean (III) class size (iv) none of
these
c) While computing mean of grouped data we assume that the frequencies are: (i) evenly
distributed over all the classes (ii) centered at the lower limits of the classes (iii) centered at
the class marks of the classes (iv) centered at the upper limit of the classes
D) What will be the upper limit of the modal class?(1) 60 (ii) 20 (iii) 40 (iv) 80
E) How many students have obtained more than 60 marks?
30 (ii) 32 (iii) 15 iv) 13​

Answer 1

Causes of land pollution are :

1) Farming

2) Mining

3) Garbage

4) factories

hope it helps you mate :)