For each of the following, state the null hypothesis and the alternative hypothesis:
a. A new cash register has been installed at the Stop One Convenience Store. The manager wants to see if the new register has made a difference in the average amount of time a customer takes to be served. The previous mean time for a customer to be served was two minutes.
b. The shipping dock receives 40-kilogram (kg) bags of flour to use in the production of the baked goods produced by Little Cakes Inc. A sample of 25 bags is taken from each shipment and weighed to ensure that the average weight is at least 40 kg. If not, the shipment is returned to the supplier.
c. An insurance company states that its average claim is $1750. However, the company auditor feels that the average amount is actually higher than $1750 and takes a sample of 60 recent claims to test his theory.
d. The college cafeteria claims that the average amount spent by a student per visit is $3.25. A random sample of 200 students is taken to see if this claim can be verified.