Homework Answers
Sol:
For the given sample mean=xbar=sum(x)/total x=16.8/8=2.1
sample standrd devaition,s=0.5371884
sample size,n=8
df=n-1=8-1=7
alpha=0.05
alpha/2=0.05/2=0.025
t critical==T.INV(0.025,7)=2.364624252
95% confidence interval for mean bending strength
xbar-t*s/sqrt(n),xbar+t*s/sqrt(n)
2.1-2.364624252*0.5371884/sqrt(8),2.1+2.364624252*0.5371884/sqrt(8),
1.650899,2.549101
95% lower limit mean bending strength = 1.650899
95% upper limit mean bending strength = 2.549101
we are 95% confident that the true popualtion mean bending strength lies in between 1.650899 and 2.549101
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