x=[27.2, 26.1, 26.0, 27.0, 25.4, 24.7, 24.3, 27.8, 25.4, 24.9];
xb=mean(x);
s=std(x);
n=length(x);
alpha=0.05;
t=tq(1-alpha,n-1);
u=t*s/sqrt(n)
abs(xb-25)