A glass manufacturer wanted to evaluate the performance of protective coating for lenses. A random

selection of lenses was given one of four different coatings, and then subjected to the same degree of

simulated abrasion. After the abrasion impairment to light was tested. The higher the number, the

worse more the lens was scratched. Put this data sheet into excel and the code using $R$ language

impairment Coating

Q$.$ Based on the data, which coating would you recommend?

a$)$ Confirm or contradict your initial findings.

Using an appropriate statistical test, explore the customer's question. Remember to declare

all appropriate hypotheses for all the tests you use. Use a significance level of $0\mathrm{.}05$ throughout.

Comment on the results of the statistical tests in the context of the customer's question.