School Commit Init

Anul 2/Semestrul 1/Probabilitati si statistica/lab_5_B1.m

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+X=[7 7 4 5 9 9 4 12 8 1 8 7 3 13 2 1 17 7 12 5 6 2 1 13 14 10 2 4 9 11 3 5 12 6 10 7];
+
+n=length(X);
+
+#oneminusalpha = input("Confidence level: (between 0 and 1)");
+oneminusalpha = 0.95;
+alpha = 1-oneminusalpha;
+
+sigma=5;
+
+m1=mean(X)-(sigma/sqrt(n))*norminv(1-alpha/2, 0, 1);
+
+m2= mean(X)-(sigma/sqrt(n))*norminv(alpha/2, 0, 1);
+
+printf("Confidence interval for the theoretical mean when sigma is known is (%4.3f, %4.3f)\n", m1,m2);
+
+m3=mean(X)-(std(X)/sqrt(n))*tinv(1-alpha/2,n-1);
+
+m4= mean(X)-(std(X)/sqrt(n))*tinv(alpha/2,n-1);
+
+printf("Confidence interval for the theoretical mean when sigma is unknown is (%4.3f, %4.3f)\n", m3,m4);
+
+v1=((n-1)*var(X))/(chi2inv(1-alpha/2, n-1));
+
+v2=((n-1)*var(X))/(chi2inv(alpha/2,n-1));
+
+printf("Confidence interval for the variance is (%4.3f, %4.3f)\n", v1,v2);
+
+s1=sqrt(v1);
+s2=sqrt(v2);
+
+printf("Confidence interval for the theoretical standard variance is (%4.3f, %4.3f)\n", s1,s2);