Respuesta :
Answer: [tex]82\%[/tex]
Step-by-step explanation:
Given: Mean [tex]\mu= 310[/tex]
Standard deviation [tex]\sigma =12[/tex]
The formula for z score : [tex]z=\dfrac{x-\mu}{\sigma}[/tex]
For x= 286
[tex]z=\dfrac{286-310}{12}\\\\\Rightarrow\ z=-2[/tex]
P value of (z=-2 )=0.0228
For x= 322
[tex]z=\dfrac{322-310}{12}\\\\\Rightarrow\ z=1[/tex]
P value of (z=1)= 0.8413
Now, the probability of students score between 286 and 322 is given by :-
[tex]P(286<x<322)=0.8413-0.0228=0.8185\approx0.82=82\%[/tex]