38 lines
1.0 KiB
Matlab
38 lines
1.0 KiB
Matlab
X=[1001.7 975.0 978.3 988.3 978.7 988.9 1000.3 979.2 968.9 983.5 999.2 985.6];
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n=length(X);
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#oneminusalpha = input("Confidence level: (between 0 and 1)");
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oneminusalpha = 0.95;
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alpha = 1-oneminusalpha;
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#The null hypothesis is: H0: u=995 (it goes togheter with u>995, the standard is meet)
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#The alternative hypothesis is: H1: u<995 (the standard is not meet)
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#Left tail test for u when sigma is unknown
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printf("This is a left tail test for the mean when sigma is inknown\n\n");
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n0=995;
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[H, PVAL, CI, ZVALUE] = ttest(X,n0,'alpha',alpha,'tail','left');
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if H==1
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printf("The null hypothesis is rejected\n\n");
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printf("The data suggests that the standard is not meet\n\n");
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else
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printf("The null hypothesis is not rejected\n\n");
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printf("The data suggests that the standard is meet\n\n");
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endif
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oneminusalpha = 0.99;
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alpha = 1-oneminusalpha;
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v1=((n-1)*var(X))/(chi2inv(1-alpha/2, n-1));
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v2=((n-1)*var(X))/(chi2inv(alpha/2,n-1));
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s1=sqrt(v1);
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s2=sqrt(v2);
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printf("Confidence interval for the theoretical standard variance is (%4.3f, %4.3f)\n", s1,s2);
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