SOLUTION: A sales clerk in the departmental store claims that 65% of the shoppers entering the store leave without making a purchase. A random sample of 60 shoppers showed that 40 of them le

Algebra ->  Probability-and-statistics -> SOLUTION: A sales clerk in the departmental store claims that 65% of the shoppers entering the store leave without making a purchase. A random sample of 60 shoppers showed that 40 of them le      Log On


   

Question 1166032: A sales clerk in the departmental store claims that 65% of the shoppers entering the store leave without making a purchase. A random sample of 60 shoppers showed that 40 of them left without buying anything. Are these sample results consistent with the claim of the sales clerk at 1% level of significance?
Answer by Boreal(15235) About Me  (Show Source):
You can put this solution on YOUR website!
Ho: prob is 0.65
Ha: prob is not 0.65
alpha P(reject Ho|Ho true}=0.01
test stat is a 1 sample proportion z=(p hat - p)/sqrt (p*(1-p)/n)
critical value is |t|>2.576
calculation is z=(0.6667-0.65)/sqrt (0.65*0.35/60)
=0.27
fail to reject Ho, and the results are consistent with the claim that the true proportion is 0.65