M.D has been surveying customers about their dining experience. survey used a scale of 1 to 5.?

Mel's diner has been surbeying their customers for the past couple of years about their dining experience in the restaurant. the survey uses a scale of one to five, five being best to indicate customer satisfaction. Mel's customer satisfaction averaged 2.5 last year, but this year it is 2.9. is the difference statistically significant? and is this pa parametric or nonparametric?

M.D has been surveying customers about their dining experience. survey used a scale of 1 to 5.?
2.9 would suggest better customer service. But the customers themselves will have different likes and dislikes.


If the 2.9 value was maintained over a vast range of customers' surveys, then yes it's statistically significant. The significance of this should show in the income.


It could be parametric if this value is maintained.
Reply:The answer depends on the sample size and assumptions about the distribution of scores. The test would be parametric.
Reply:Really depends on the sample size, you may have to be concerned with time of day, and type of meal as well. New wait staff? How busy it is? Lots of posssible factors depending on how many times it was taken. Assuming all else is the same then size is most critical.