Long Answer TypeA survey regarding the heights (in cm) of 50 girls of class X of a school was conducted and the following data was obtained:
|
Height in cm |
120 - 130 |
130 - 140 |
140 - 150 |
150 - 160 |
160 - 170 |
Total |
|
Number of girls |
2 |
8 |
12 |
20 |
8 |
50 |
Find mean, median and mode of the following data:
|
Classes |
Frequency |
|
0-20 |
6 |
|
20-40 |
8 |
|
40-60 |
10 |
|
60-80 |
12 |
|
80-100 |
6 |
|
100-120 |
5 |
|
120-140 |
3 |
Find mean, median and mode of the following data:
|
Classes |
Frequency |
|
0 - 50 |
2 |
|
50 - 100 |
3 |
|
100 - 150 |
5 |
|
150 - 200 |
6 |
|
200 - 250 |
5 |
|
250 - 300 |
3 |
|
300 - 350 |
1 |
The following table gives the daily income of 50 workers of a factory :
|
Daily income (in Rs.) |
No. of Workers |
|
100-120 |
12 |
|
120-140 |
14 |
|
140-160 |
8 |
|
160-180 |
6 |
|
180-200 |
10 |
Find the Mean, Mode and Median of the above data.
Short Answer TypeFind the mode, median and mean for the following data :
|
Marks Obtained |
Number of Students |
|
25-35 |
7 |
|
35-45 |
31 |
|
45-55 |
33 |
|
55-65 |
17 |
|
65-75 |
11 |
|
75-85 |
1 |
Long Answer TypeThe table given below shows the frequency distribution of the scores obtained by 200 candidates in a BCA examination.
|
Score |
No. of candidates |
|
200-250 |
30 |
|
250-300 |
15 |
|
300-350 |
45 |
|
350-400 |
20 |
|
400-450 |
25 |
|
450-500 |
40 |
|
500-550 |
10 |
|
550-600 |
15 |
Draw cumulative frequency curves by using (i) 'less than series', (ii) 'more than series'.
Draw both types of cumulative freqneucy curve on the same graph paper and then determine the median.
|
Marks obtained |
No. of students |
|
50-60 |
4 |
|
60-70 |
8 |
|
70-80 |
12 |
|
80-90 |
6 |
|
90-100 |
6 |
Draw 'less than' and 'more than' ogive curve from the following and indicate the value of median.
|
Marks |
No. of students (f) |
|
0-5 |
7 |
|
5-10 |
10 |
|
10-15 |
20 |
|
15-20 |
13 |
|
20-25 |
12 |
|
25-30 |
10 |
|
30-35 |
14 |
|
35-40 |
9 |
|
Daily Income (in Rs.) |
Number of Workers |
|
100-120 |
12 |
|
120-140 |
14 |
|
140-160 |
8 |
|
160-180 |
6 |
|
180-200 |
10 |
During the medical check-up of 35 students of a class their weights were recorded as follows:
|
Weight (in kg.) |
No. of Students |
|
38—40 |
3 |
|
40—42 |
2 |
|
42—44 |
4 |
|
44—46 |
5 |
|
46—48 |
14 |
|
48—50 |
4 |
|
50—52 |
3 |
Draw a less than type and a more than type ogive from the given data. Hence obtain the median weight from the graph.
|
Classes |
f |
c.f. |
c.f. |
||
|
38-40 |
3 |
3 |
(40, 3) |
35 |
(38, 35) |
|
40-42 |
2 |
5 |
(42, 5) |
32 |
(40, 32) |
|
42-44 |
4 |
9 |
(44, 9) |
30 |
(42, 30) |
|
44-46 |
5 |
14 |
(46, 14) |
26 |
(44. 26) |
|
46-48 |
14 |
28 |
(48, 28) |
21 |
(46, 21) |
|
48-50 |
4 |
32 |
(50, 32) |
7 |
(48, 7) |
|
50-52 |
3 |
35 |
(52, 35) |
3 |
(50, 3) |
We plot the points (40, 3), (42, 5), (44, 9), (46, 14), (48, 28), (50, 32), (52, 35). We join these points with a smooth curve to get the 'less than' ogive as shown in Fig. 14.20.
Then, we plot the points (38, 35), (40, 32), (42, 30), (44, 26), (46, 21), (48, 7), (50, 3) on the same axes. By joining these points with a smooth curve to get 'more than' ogive. Since, the two curves intersect at the point, whose abscissa is 47 (approx). Hence, the required median weight is 47 kg (approx.).
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