Question 1183826
Ho: mu1=mu2
Ha: mu1 NE mu2
alpha=0.05 p{reject Ho|Ho true}
test is a z
critical value is |z|> 1.96 
z=(14.6-15.4)/2.5/sqrt(35)
=-0.8*sqrt*35)/2.5
=-1.89
 fail to reject Ho and insufficient evidence to conclude there has been a change at the 5% level.
p-value=0.058