Math, asked by pranay8601, 7 months ago

If the median of the data 15 and 16 and 17 and 2 X + 4 and 3 x minus 2 and 20 and 21 and 22 written in ascending order is 18.5 then X is equals to

Answers

Answered by OmRajeDongare
1

Answer:

Step-by-step explanation:

The given observations are,

6,7,x−2,x,18,21

Number of observations (n)=6   [ even ]

⇒  Median=  

2

3  

rd

obs+4  

th

obs

​  

 

⇒  16=  

2

x−2+x

​  

 

⇒  32=x−2+x

⇒  32=2x−2

⇒  34=2x

∴  x=17

∴  The observations becomes,

6,7,15,17,18,21

x

=  

6

6+7+15+17+18+21

​  

=  

6

84

​  

=14

Variance(σ  

2

)=  

6

(6−14)  

2

+(7−14)  

2

+(15−14)  

2

+(17−14)  

2

+(18−14)  

2

+(21−14)  

2

 

​  

 

                         =  

6

(−8)  

2

+(−7)  

2

+(1)  

2

+(3)  

2

+(4)  

2

+(7)  

2

 

​  

 

                         =  

6

64+49+1+9+16+49

​  

 

                         =  

6

188

​  

 

                         =  

3

94

​  

 

                         =31  

3

1

​  

 

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