Activity

For each of the following questions of interest formally state the null and alternative hypotheses using symbols.

  1. Are children exposed to pesticides more likely to develop ADHD (attention-deficit/hyperactivity disorder) than those who aren’t exposed?

  2. Is the average age of ICU patients at this hospital greater than 50 years?

  3. If you want to remember something, does taking a nap work better than having some caffeine?




Scroll down for answers


Answers

  1. Are children exposed to pesticides more likely to develop ADHD (attention-deficit/hyperactivity disorder) than those who aren’t exposed?

    \[ H_0: p_{\text{exposed}} = p_{\text{not exposed}} \\ H_1: p_{\text{exposed}} > p_{\text{not exposed}} \]
    where \(p\) is the proportion of children diagnosed with ADHD.

    Alternatively,

    \[ H_0: p_{\text{exposed}} - p_{\text{not exposed}} = 0 \\ H_1: p_{\text{exposed}} - p_{\text{not exposed}} > 0 \]

  2. Is the average age of ICU patients at this hospital greater than 50 years?

    \[ H_0 : \mu = 50 \\ H_1 : \mu > 50 \]
    where \(\mu\) is the population mean age (in years) in the hospital’s ICU unit.

  3. If you want to remember something, does taking a nap work better than having some caffeine?

    \[ H_0 : \mu_{\text{nap}} = \mu_{\text{caffeine}} \\ H_1 : \mu_{\text{nap}} > \mu_{\text{caffeine}} \]
    where \(\mu\) is the average number of items remembered from a list (that the researcher has developed and used for testing the participants).

    Alternatively:

    \[ H_0 : \mu_{\text{nap}} - \mu_{\text{caffeine}} = 0\\ H_1 : \mu_{\text{nap}} - \mu_{\text{caffeine}} > 0 \]