Question

Stemming from concern over childhood obesity, researchers investigated whether children might be as tempted by toys as by candy for Halloween treats. Test households in five Connecticut neighborhoods offered two bowls to trick-or-treating children: one with candy and one with small toys. For each child, researchers kept track of whether the child selected the candy or the toy. The research question was whether trick-or-treaters are equally likely to select the candy or toy. More specifically, we will investigate whether the sample data provide strong evidence that trick-or-treaters have a tendency to select either the candy or toy more than the other.

What are the observational units? What is the variable, and what type of variable is it?

What is the population of interest?

Was the sample selected randomly from the population?

What is the parameter of interest? What is the null hypothesis, in words? What is the alternative hypothesis, in words?

Answer 1

Observational units: bowls of candies and toys.

Variable: Selection of candy or toy. If X is the variable, then X= selection of the bowl of candies (or toys).

Type of variable: Dummy variable.

X=1, if a child selects candy bowl

X=0, if the child selects the toy bowl.

Population: children

Sample: 5 children from neighbouring households in Connecticut

Yes, the sample is chosen randomly from the population.

Parameter: p= proportion of children selecting candies.

Null Hypothesis: p=1/2 ie, probability of choosing candies or toys is equally likely

Alternative hypothesis: p not equal to 1/2, ie, choosing candies or toys by children is not equally probable