to find out whether a new serum will arrest leukemia,9 mice,all with an advanced
ID: 3178214 • Letter: T
Question
to find out whether a new serum will arrest leukemia,9 mice,all with an advanced stage of the disease,all recipes selected.five mice receive the treatment and 4 do not. survival times in year from the time the experiment commenced are as follows
treatment 2.1 5.3 1.4 4.6 0.9
no treatment 1.9 0.5 2.8 3.1
1_at 5% level of significance can the serum be side to Effective?assume the two distribution are normally distribution are normally distribution are normally distributed with equal variances
2_ find appropriate bound
Explanation / Answer
the summary statistics is calcualted as using ms-excel
here we use t-test and
t=(mean1-mean2)/((sp*(1/n1 +1/n2)1/2) and sp2=((n1-1)s12+(n2-1)s22)/n and with df is n=n1+n2-2
=(2.86-2.075)/(1.6741*sqrt(1/5 + 1/4))=0.699
sp2=((n1-1)s12+(n2-1)s22)/n=(5-1)*1.9705*1.9705+(4-1)*1.1673*1.1673)/(5+4-2)=2.8028
sp=1.6741
crictical t(0.05,7)=2.3646 is more than the calculated t=0.699, so we can say that both treatdment are not statisticaly different at 5% level of significance
(2) stanard error of difference of mean=(sp*(1/n1 +1/n2)1/2)=(1.6741*sqrt(1/5 + 1/4))=1.123
(1-alpha)*100% confidence interval for difference of mean=difference mean±t(alpha/2,n-1)*SE(difference of mean)
95% confidence interval =(2.86-2.075)±t(0.05/2, 7)*1.123=0.785±2.3646*1.123=0.785±2.655=(-1.87,3.44)
requied bound is (-1.87,3.44)
treatment(x) no treatment(y) 2.1 1.9 5.3 0.5 1.4 2.8 4.6 3.1 0.9 n= 5 4 mean= 2.86 2.075 s= 1.970532923 1.167261753Related Questions
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