Question 1186334
Ho: t=85 min
Ha: t NE 85 min
alpha=0.05 p{reject Ho|Ho true}
test stat is a z
critical value is |z|>1.96
test stat is z=(x bar=mean)/sigma/sqrt(n)
=(80.5-85)/25/sqrt(135)
=-4.5*sqrt(135)/25=-2.09
reject Ho,the true time is not 85 minutes but is fewer.  
p-value=0.036.