In planning a study on the number of days in the last 30 that high school students texted while driving sometime during the day, a researcher states the hypotheses as H 0 : ¯ x = 15 days H a : ¯ x > 15 days What’s wrong with this? Hypotheses are statements about statistics, not parameters. The research question should not be about the population mean μ but should be about the sample mean ¯ x ˉ . Hypotheses are statements about parameters, not statistics. The research question should not be about the sample mean ¯ x , but should be about the population mean, μ . The null and alternative hypotheses need to be switched. There is nothing wrong with this statement.