Question 1061776
Ho: There has been no change mu o=mu
Ha: There has bee a change mu o ne mu
alpha=0.05 prob reject Ho|Ho is true
test statistic is z.
critical value is |z|>1.96
calculation z=(x bar-mean)/sigma/sqrt(30)
t=7000*sqrt(30)/21000=(1/3)*sqrt(30)=1.83
This is not greater than 1.96
Fail to reject Ho: insufficient evidence to say that there was a change.
p-value=0.068.