Question

mean of 11 observation is 65. Later on it observe 75 was misread as 57. Find the correct mean​

Answer 1

Answer:

Step-by-step explanation:

∑x/n=x

∑x/11=65

incorrect value of ∑x=11*65=715

correct value of ∑x= incorrect value of ∑x- incorrect observation +correct      observation    

             =715-57+75      

             =733    

correct mean=   correct value of ∑x / n    

                       =733/11

                       =66.64  

Answer 2

Answer:

66.63

Step-by-step explanation:

let the sum of observation be x

no. of observation=11

mean=65

so we can conclude that

65=sum of observation/11

now we can solve it

So,

65=sum of observation/11

65×11=sum of observation

715=sum of observation

new sum =715-57+75=733

now we can find new mean by the formula(mean=sum of observation/no. of observation)

733/11=66.63 and a sleeping line on 63