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Hypothesis testing with Tutti Frutti

Tutti Frutti used to be my favourite candy. I haven't eaten it in a while but one day I somehow got curious whether the types of candies are distributed evenly. There are 9 possible types of candy (3 colours and 3 shapes), so the proportion of each should be 1/9. But is it?

To answer this question, I bought 30 packs of Tutti Frutti. I then counted the number of each type of candy in each pack and recorded the results in a spreadsheet. After that, I conducted a hypothesis test for each type of candy to determine if the proportion of that type is significantly different from what is expected (which is 1/9).

Photo of Tutti Frutti candies sorted by colour and shape

It turned out that most of the candy types are evenly distributed, except for one. There are more red frogs (M = 14.8%, SD = 9.5%) than the population norm 11.1%, t(29) = 2.1006, p = .0445. This is enough evidence to reject the null hypothesis under alpha = 0.05.

I then performed the same analysis for each colour and shape as well. Turns out that in general there are more red coloured Tutti Fruttis (M = 39.1%, SD = 10.2%) than others, t(29) = 3.0931, p = 0.0044.

Grid of histograms showing proportion distributions for each candy type