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Byju's Answer
Standard X
Mathematics
Finding Mean for Grouped Data When Class Intervals Are Not Given
If the mean o...
Question
If the mean of the following distribution is 54, find the value of p:
Class :
0−20
20−40
40−60
60−80
80−100
Frequency :
7
p
10
9
13
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Solution
Consider the table given below:
Class Interval
Frequency(f
i
)
Class Mark(x
i
)
f
i
x
i
0–20
7
10
70
20–40
p
30
30p
40–60
10
50
500
60–80
9
70
630
80–100
13
90
1170
∑
f
i
=
39
+
p
∑
f
i
x
i
=
2370
+
30
p
It given that the mean of the distribution is 54.
∴
Mean
=
∑
f
i
x
i
∑
f
i
⇒
2370
+
30
p
39
+
p
=
54
⇒
2370
+
30
p
=
2106
+
54
p
⇒
54
p
-
30
p
=
2370
-
2106
⇒
24
p
=
264
⇒
p
=
264
24
=
11
Hence, the value of p is 11.
Suggest Corrections
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Q.
If the mean of the following frequency distribution is 54, find the value of p. [CBSE 2006C]
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Q.
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