x=[45,43,41,49,46,36,47,51,48,40,37,44,49,49,52,51,47,49,46,48]/10
n=length(x)
m=mean(x),sigma=.4;
mi0=4.4;Y=(m-mi0)*sqrt(n)/sigma
[h,p,ci,zval]=ztest(x,4.4,0.4,0.05,'right')
x=[10.24,10.12,9.91,10.19,9.78,10.14,9.86,10.17,10.05];mi0=10;
[h,p,ci,zval]=ztest(x,4.4,0.4,0.05,'right')
alpha=.05;q=norminv(1-alpha)
x=[45,43,41,49,46,36,47,51,48,40,37,44,49,49,52,51,47,49,46,48]/10
n=length(x),m=mean(x),sigma=.4;mi0=4.4;Y=(m-mi0)*sqrt(n)/sigma
alpha=.05;q=tinv(1-alpha/2,n-1)
[h,p,ci,stats]=ttest(x,10,0.05,'both')
z=[1880,1920*ones(1,4),1960*ones(1,12),2000*ones(1,14),...
2040*ones(1,15),2080*ones(1,3),2120];sigma2=45^2;n=length(z),
format long g;v=var(z),chi2=(n-1)*v/sigma2
format,alpha=.01;qd=chi2inv(alpha/2,n-1),qh=chi2inv(1-alpha/2,n-1)
x1=[2432,2448,2531,2475,2510,2517,2540,2525,2528,2501,2473,...
2509,2532,2527]/10;x2=[2504,2502,2511,2493,2499,2502,2511]/10;
v1=var(x1),v2=var(x2),F=v1/v2