Jackie noticed that she had to pay a sales tax for the dress she bought at the store. What is sales tax? The amount someone pays to buy a specialty item.
A percentage of total sales that is collected on behalf of the state, county, or local government.
A percentage of total sales given back to the store.
A percentage of total sales to be distributed to shoppers at a later time.

An automobile assembly line operation has a scheduled mean completion time, μ, of 12 minutes. the standard deviation of completion times is 1.6 minutes. it is claimed that, under new management, the mean completion time has decreased. to test this claim, a random sample of 33 completion times under new management was taken. the sample had a mean of 11.2 minutes. assume that the population is normally distributed. can we support, at the 0.05 level of significance, the claim that the mean completion time has decreased under new management? assume that the standard deviation of completion times has not changed.