Example Direct method (Part - 7) - Statistics Video Lecture - Class 10

hello friends this video statistics part
7 is brought to you by exam fear calm no
more fear from exam before watching this
video please make sure that you have
washed part 1 to part 6 a survey was
conducted in which they collected the
following data recording the number of
plants in 20 houses in locality you
define mean number of plant for house
this is already a group data so if you
see 0 to 2 2 to 4 4 spine sorry 4 to 6
the difference is always to correct and
it start and end with 4 starts with four
end with six starts with 6 this is one
symptom will be done already a group
reader correct the difference is always
true this is my grouping and I have to
find the mean and I will use direct
method why because the data is very
simple asthma so let me form this table
actually the same thing I wrote in this
form because I want to write here now
the first thing I told is to find the
meat what you do you have to find the
value of x I see this number of lines
and number of houses all say images
stored in this fashion so X is nothing
but min plus 90 by module 0 plus 2
divided by 2 that is 2 1 plus 4 6
divided by 2 it is 3 4 plus 6 10 divided
by 2 is 5 6 plus 8 14 divided by 2 7 8
plus 10 18 / - 9 10 plus 12 22 divided
by 2 11 12 plus 14 there is 26 event
returning so I got the value of x eyes
next thing is going to find X IFI
because the formula is Sigma fi x iyb I
see Wi-Fi certified fi x i1 into 1 is 1
chain 2 2 6 5 into 1 is 5 75359 - 554
2011 22 3 into 13 is not
you add all this you add all this what
you get is 160 if you add all this
summation of FI what you get is 20 you
can do this 3 plus 2 5 plus 6 11 16 + 4
you know so we can add you get 160 and
directly we know the formula is
summation is Sigma fi x fi Sigma fi this
is nothing but 162 bye Wendy
so what if it is eg 1 so the point 1
this is my main value this is the mean
number of plants per shrooms this is the
value mean number of plants per house
mean number of plants per house and that
value is eight point one very simple
just use direct method and I'd method
you to find X I first plus we are
assuming that this fi Duvall's and on
the middle of this valley middle is 0
plus 2 by 2 so X is all middle of these
two upper lower limit to the upper limit
divided by 2 we take off my example this
example will try to solve the thing as
you need method the following
distribution shows the pocket money
allowance of a children in the locality
the main allowance 18 - peas need to
find the missing frequency this will do
using as you mean method for this the
first thing is we should draw this graph
steeple actually and then assuming
method we know the formula s means a
plus Sigma fi di by Sigma fi till assume
the missing written C to be F now the
first thing is that we first observed as
a result
group data or not if you see is a root
beta because this ends the 13 starts
four thirty fifteen fifteen seventeen
seventeen nineteen nineteen twenty one
twenty one this video also to the
difference if you see is to the class
interval is to win all the case so first
thing is passed
it is a group data now we have to fight
X I X I we know is nothing but the lower
range does upper is divided by 2 xi plus
30 divided by two there is 24 by 2 that
is 12 13 plus 15 the list when he made
by ot 17 + 15 32 but there is 16 17
blossom I in team but there is 18
correct and this guy is 19 plus 21 by to
do this 20 21 + 23 by 44 boiling
disraeli 2 + 23 + 25 that is 48 5 in
verse 24 I got the value of x eyes in
case of as you mean we assume one value
to the mean so let assume the mean value
to be AV let me assume this one ade oba
T correct see you are in confusion
whether we should select a from this
Lord for this thought you know that di
is X I minus K so you should select a
from Xiao Li and when this commemorative
actually if you want to select a a
should be from X I only so a is 1 by X I
so the middle value is 18 so I assume a
to be X I so D will be X I minus ei
there is 12 minus 80 that is minus 6 14
minus 18 is minus 4 16 minus 18 minus 2
18 minus 8 is 0 20 - 18 to 22 minus 8 is
4 and 24 months it
6.now let you find fi di so to multiply
this fi with DI 7 into minus 6 minus 42
6 into minus 4 minus 1 D for my into
minus 2 a minus 18 0 F into 2 is 2 F 5
into 4 xx and 684 Wendy so if you add
this there becomes 2 F minus 40 action
if you add this this becomes 2 8 minus 4
and this value if you know is nothing
but 44 plus 1/2 this permission you add
this now it's very simple we'll just
apply the formula the question says mean
is 18 so that is 18 is equal to is how
much assumed is 18 only plus Sigma F
idea is to have minus 14 by 44 plus f-18
engine gas him so what I get is you have
minus 40 by 44 plus F equal to 0 or what
I get to I have minus 40 is equal to 0
or I get F basically Wendy so the
missing frequency this guy is nothing
but 20 and that is my answer where is
simple I assume the base is equal to bf
and then using as you mean method I
found that the mean came out to be 2f
minus 40 by 44 plus F plus VD and that
is equal to 18 I sword corn bread of F
to be 20 thank you
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