Misleading chart
This is an archived article that was published on sltrib.com in 2013, and information in the article may be outdated. It is provided only for personal research purposes and may not be reprinted.

In "Does Costco save you money?" (Tribune, May 25), the bar graphs comparing prices at the bulk grocery stores Costco and Sam's Club with grocers Smith's and Harmons were misleading and darn unhelpful.

Take the chart on Bush's Original Baked Beans. The visual comparison with colored bar shows that at $12 Costco is way more expensive — more than six times! — Harmon's under $2 price.

But then there's the fine print: Costco's $11.99 is for eight 16.5-ounce cans, while Harmons is $1.79 for one 28-ounce can — the bars heights compare nothing relevant. (And doesn't Harmons sell 16.5-ounce cans, which would be a fairer comparison?)

Heck, even Smith's aisle price signs helpfully translate prices to a cost-per-ounce rate, but not The Trib's "comparative" chart. So I got out my iPhone calculator: Costco is $.0.91 per ounce, and Harmons is $.064 per ounce. Per ounce, Costco still costs more than Harmons' bulk can, but 50 percent more, not the whopping 669 percent shown in The Trib's misleading bar graph.

Way back in my high school statistics class, I learned about misleading comparisons and representations, so I'm surprised The Tribune's professionals aren't more careful.

Mark Smith

Salt Lake City