a)번 젤처음 답변지가 3개가다른데..
이게 1번답변 - 이건 x-평균/루트 n 한것같고
P[X<5] =P[(5-15)/루트40]=P[Z<-1.58]
Using normal probability table;
P[z<-1.58]=0.0571
=5.71%
There is a 5.71% probability that a visitor stay less than 5 minutes.
2번답변이 x-평균/그냥 샘플 n
5-15/5 = -2 // p(x<z)= 0.02275 -> 2.27 percent
3번 답변 / x-평균/(샘플표준편차/루트40)
5-15/(5/루트40)
난3번같은데.. 고수형들알려줘
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c번문제도
모범답안 1은
h0 u<16
ha : u>16
p value = p(z>0.00) = 1-p(z<0.00) = 1.0.5000 =0.5000
the null hypothesis cannot be rejected since the p value is larger than 0.05
모범답안2는
h0 x(new) = x(old)
h1 : x(new ) > x(old)
z = x(new)-x(old) / 루트(s(new)2/n(new) - s(old)2/n(old)
z= 16-15/루트(25/40 -36/45)
=0.8443
critizal z is 1.645 . calculated value < critical value , do not reject null. people do not stay longer on the new website
모범답안2가맞지?
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