Question

the avg mark of class of twenty students is 64 if three students whose marks r 32 ,28and 34 r removed​

Answer 1

Step-by-step explanation:

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Answer 2

Answer:

Here we should find the the average mark 17 students using the given data.

Final Answer:

                Average mark of 17 students $=69.764$

Approximate Average mark of 17 students $=70$

Step-by-step explanation:

From the given question,

Total number of students in the class $=20$

• That 20 students consider as, $s_{1},s_{2},s_{3}....s_{20}$

Average mark of 20 students $=64$

Average mark of 20 students should be written as,

     $Average \hspace{1mm}mark\hspace{1mm} of\hspace{1mm} 20 students=\frac{Sum\hspace{1mm} of \hspace {1mm} students\hspace{1mm} marks}{No\hspace{1mm} of\hspace{1mm} students}$

                                                $64=\frac{s_{1 }+s_{2}+s_{3}+.....+s_{ 20} }{20}$

               $s_{1 }+s_{2}+s_{3}+.....+s_{ 20} =64\times20$

               $s_{1 }+s_{2}+s_{3}+.....+s_{ 20} =1280$

• From here three students marks 32 ,28and 34 are removed​.So that now we should find average of 17 students marks. It should be written as,

Total mark after the removal of 3 students $= 1280-(32 +28+34 )$

                                                                      $=1186$

                     Average mark of 17 students $=\frac{1186}{17}$

                     Average mark of 17 students $=69.764$

Approximate Average mark of 17 students $=70$

Final Answer:

                Average mark of 17 students $=69.764$

Approximate Average mark of 17 students $=70$