5. The distribution below shows the number of wickets taken by bowlers in
Mathematics CLASS
Duration: 60
Mins. X Max. Marks : 40 Topic : Statistics
one-day cricket matches. Find the mean number of wickets by choosing a
suitable method. What does the mean signify?
Number
of
Wickets
20 - 60 60 - 100 100 - 150 150 - 250 250 - 350 350 - 450
Number
of
Bowlers
7 5 16 12 2 3
Share
Answer:
Number of Wickets Number of Bowlers (f
i
) Class Mark (x
i
) f
i
x
i
20−60 7
2
20+60
=40 7×40=280
60−100 5
2
60+100
=80 5×80=400
100−150 16
2
100+150
=125 16×125=2000
150−250 12
2
150+250
=200 12×200=2400
250−350 2
2
250+350
=300 2×300=600
350−450 3
2
350+450
=400 3×400=1200
∑f
i
=45 ∑f
i
x
i
=6880
This problem can be solved using direct method as class interval is different.
We know tha,
Mean (
x
)=
∑f
i
∑f
i
x
i
Now, the required mean is,
x
=
45
6880
=152.89