The Managing Director of a Breakfast Cereal Manufacturer Believes That

Essay

The managing director of a breakfast cereal manufacturer believes that families in which both spouses work are much more likely to be consumers of his product than those with only one working spouse. To prove his point, he commissions a survey of 300 families in which both spouses work and 300 families with only one working spouse. Each family is asked whether the company's cereal is eaten for breakfast. The results are shown below. $$\begin{array} { | l | l | l | } \hline & \begin{array} { l } \text { Two spouses } \\\text { working }\end{array} & \text { One spouse working } \\\hline \text { Eat cereal } & 114 & 87 \\\hline \text { Don't eat cereal } & 186 & 213 \\\hline\end{array}$$ Do these data provide enough evidence at the 1% significance level to infer that the proportion of families with two working spouses who eat the cereal is at least 5% larger than the proportion of families with one working spouse who eats the cereal?