No.
35 - 40
9. Following table gives the marks scored by students in an examination :
30 - 35
25 - 30
20 - 25
15 - 20
10 - 15
0 - 55 - 10
2.
5.
8
16
15
7
24
Marks
No. of students
Calculate the mean mark, correct to two decimal places.
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Answers
Answered by
1
Step-by-step explanation:
ANSWER
Direct method
size
x
f
xf
0-10
5
20
100
10-20
15
24
360
20-30
25
40
1000
30-40
35
36
1260
40-50
45
20
900
mean =
∑f
∑fx
=
140
3620
=25.857
Assumed mean method
size
x
u=x-25
f
uf
0-10
5
-20
20
-400
10-20
15
-10
24
-240
20-30
25
0
40
0
30-40
35
10
36
360
40-50
45
20
20
400
mean =A+
∑f
∑fu
=25+
140
120
=25.875
Step deviation method
size
x
d=x-25
u=(x-25) / 10
f
uf
0-10
5
-20
-2
20
-40
10-20
15
-10
-1
24
-24
20-30
25
0
0
40
0
30-40
35
10
1
36
36
40-50
45
20
2
20
40
mean =A+h×
∑f
∑fu
=25+10×
140
12
=25.875
Answered by
0
Answer:
5
10
15
20
25
Step-by-step explanation:
30
56899088999
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