An advertisement for a new toothpaste claims that it reduces cavities of children in their cavity-prone years. Cavities per year for their age group are normal with mean 3 and standard deviation 1. A...

Extracted text: An advertisement for a new toothpaste claims that it reduces cavities of children in their cavity-prone years. Cavities per year for their age group are normal with mean 3 and standard deviation 1. A study of 2500 children who used their toothpaste found an average of 2.95 cavities per child. Assume that the standard deviation of the number of cavities of a child using this new toothpaste remains equal Problem 1. to 1. (a) Are these data strong enough, at the 5 percent level of significance, to establish the claim of the toothpaste advertisement? Use the test statistic approach. (b) Without doing any recalculation, do you think there would be a change in the conclusion in part (a) if you decrease the level of significance to 1 percent? Explain your answer.