(5.5 points) The extent to which an infant's health is affected by parental smoking is an important public health concern. The following data are the urinary concentrations of cotinine (a metabolite of nicotine); measurements were taken both from a sample of infants who had been exposed to household smoke (Group 1) and from a sample of unexposed infants (Group 2). The data are

	Exposed to Household Smoke	Unexposed
Sample Size	8	7
Sample Mean	116.00 ng/mL	31.29 ng/mL
Sample Standard Deviation	59.99 ng/mL	47.07 ng/mL

Is there evidence that mean cotinine level for infants exposed to household smoke is greater than the mean cotinine level for unexposed infants? Test this hypothesis using a significance level of 1%.

a) (0.5 points) What is the outcome variable? Is this outcome variable considered to be continuous or dichotomous?

b) (1 point) Set up the appropriate null and alternative hypotheses for this study.

c) (1 point) Select the appropriate test statistic. Should a z or t test statistic be used for this hypothesis test? Explain your reasoning and/or show your work.

d) (0.5 points) Write out the decision rule for this hypothesis test. Make sure to include the appropriate z or t critical value. e) (1.5 points) Compute the appropriate test statistic for this hypothesis test. Show your work.

f) (1 point) Make a decision using the decision rule in (d) and the calculated test statistic in (e). Write out an appropriate conclusion.