xbar1=[204.4;556.6];
xbar2=[130.0;355.0];
S1=[13825.3 23823.4;23823.4 73107.4]
n1=45;
S2=[8632.0 19616.7;19616.7 55964.5];
n2=55;
Spooled=(1/(n1+n2-2))*((n1-1)*S1+(n2-1)*S2)
T2=(xbar1-xbar2)'*inv(((1/n1)+(1/n2))*Spooled)*(xbar1-xbar2)
lprop=inv(Spooled)*(xbar1-xbar2)
