Spending a penny in supermarkets
This article provides much information which could be used as a basis for classroom discussion, for assessment items, for graphing activities, or for surveys students might conduct themselves. The article contains another feature of many media stories with statistical content: the "typical shopper", a sample of size one. Students may like to compare Mrs Inches with the average shopper described in an earlier paragraph. Which is more representative of the average shopper?
Teachers who would like to discuss different kinds of average can focus on the seventh paragraph which begins, "The average shopper is likely to be...". Using this paragraph and the accompanying table, the average shopper has been defined by model values, that is the highest percentage among the categories for that characteristic. The female category of shoppers was the largest (76%), as was the "married" group (66%), and the "no children" group. The model age group (35-45 with 29%) was used to say that the average shopper was about 40. This is the middle value of the category and students might like to discuss how accurate they think this value might be. Would a median or mean value have been a better choice. If respondents ticked boxes of 10-year intervals this may be the best choice but it would be very instructive to see a bar chart to show the distribution of ages of shoppers. It could be that the distribution is skewed and the model group (29%) is at the low end of the age intervals.
Students should think of questions they would ask the people who ran the survey. Questions might include the following:
The response to the question about shopping at a major supermarket chain might be influenced by where the survey took place.
Students might like to plan and carry out their own surveys about shopping habits to compare with the results in this article.
Where to next?
Student Questions for this article
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