A researcher claims that the mean sodium content of sandwiches at Restaurant A is less than the mean sodium content of sandwiches at Restaurant B. The mean sodium content of 22 randomly selected...

A researcher
claims that the mean sodium content of sandwiches at Restaurant A is less than the mean sodium content of sandwiches at Restaurant B.
The mean sodium content of
22
randomly selected sandwiches at Restaurant A is
670 mg. Assume the population standard deviation is
20
mg. The mean sodium content of
28
randomly selected sandwiches at Restaurant B is
690 mg. Assume the
population standard deviation is 30 mg.

At
α = 0.05, is there enough evidence to support the claim?

Use the P-value method. Clearly show all steps.