rkld-445428415& nld-8&flushed-true3dld-4674232;&icent; MATH 1342.21420 Homework:
ID: 2922342 • Letter: R
Question
Explanation / Answer
Ans:
Given that
mean=6
standard deviation=1.2
when n=4
standard error of mean=1.2/sqrt(4)=1.2/2=0.6
when n=9
standard error of mean=1.2/sqrt(9)=1.2/3=0.4
standard error is small for n=9,because as the n increases,standard error decreases.
For n=9
z(4.8)=(4.8-6)/0.4=-1.2/0.4=-3
z(7.2)=(7.2-6)/0.4=1.2/0.4=3
P(z<-3)+P(z>3)=0.0027
For n=4
z(4.8)=(4.8-6)/0.6=-1.2/0.6=-2
z(7.2)=(7.2-6)/0.6=1.2/0.6=2
P(z<-2)+P(z>2)=0.0455
So,figure with smaller area at tail ends(0.0027) will be for n=9.
As,standard error is small,test statistic is Less likely to be more than 1.2 pounds away from the mean.
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