Question

Problem: Suppose we know the average number of cavities by age 30 years old for the US population is Approximately Normal -Mean-7 Standard deviation σ --3 Residents of Happytown have been adding fluoride to their water for decades and would like to know whether this has lessened the incidence of cavities. The parameter of interest is u-average number of cavities for all Happytown residents at age 30. Consider the sample mean of an SRS of n9 Happytown residents who are 30 years old. 1. What are the null and alternative hypotheses for this test? Null: mu- Alternative: mu Assuming the null is true, what are the mean and standard deviation of the sample mean of an SRS of n-9 Happytown residents who are 30 years old, assuming. that σ-3 for the Happytown residents? Recall that for the sample mean X 2. The mean of x the population mean μ-m The standard deviation of x- 2222

Need help getting the null and alternative. As well as answer to part 2.

Answer 1

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