Question

How to do C and D for following:

Answer 1

$\\ The\ scores\ of\ 95\%\ of\ the\ students\ are\ between\ a\ lower\ value\ of\\ {286-2(32)=286-64=222\ \ \ and\ an\ upper\ value\ of\ 286+2(32)=286+64=350}$

The scores of 95 %  of the students are between a lower value  of  222 and  an  upper value of 350

$\\ From\ normal\ distribution \ table \\ (c)\ z>-0.8\\ P(z>-0.8)=1-p(z<-0.8)=1-0.2119=\boldsymbol{0.7881}\\ \\ (d)\ -0.8<Z<1.91\\ {P(-0.8<Z<1.91)=P(z<1.91)-P(z<-0.8)=0.9719-0.2119=\boldsymbol{0.7600}}$

normal distribution From (c)0.8 P(z >-0.8)-1-Plz <-0.8) table 1-0.21 19 0.7881 (d)-0.8< Z<1.91 P(-0.8 < Z < 1.91) = P(z < 1.91)-P(z <-0.8) = 0.9719-0.2119 0.7600