There are 505 full-service restaurants in North Dakota. The mean number of seats per restaurant is 74.1. [Source: Data based on the 2002 Economic Census from the US Census Bureau.] Suppose that the true population mean µ = 74.1 and standard deviation σ = 21 are unknown to the North Dakota tourism board. They select a simple random sample of 45 full-service restaurants located within the state to estimate µ. The mean number of seats per restaurant in the sample is M = 78.3, with a sample standard deviation of s = 17.8.

The standard deviation of the distribution of sample means (that is, the standard error, σM

M

) is . (Note: Although µ and σ are unknown to the North Dakota tourism board, they are known to you for the purposes of calculating these answers.)

The standard or typical average difference between the mean number of seats in the 505 full-service restaurants in North Dakota (µ = 74.1) and one randomly selected full-service restaurant in North