“The spread of the data for the female trout is a bit larger than the spread for male trout. This is probably because more female trout were caught. Female trout also have the smallest minimum of 405mm and the largest maximum of 625mm which also suggests that more female trout were caught.”
Okay, from the point of view of ‘what I see in the picture’, the person is right, as we see in the picture the upper middle ‘box’ (students prefer to call it) is wider than the bottom box (fig). But my concern is with the second part, the justifying line; student was not clear about the one thing in life i.e if we investigate a section or a group of items or people, more the better (if we are unbiased) as it will give us better or clearer picture of the group. In statistics it is called, ‘more representative’. Reminds me of the time I went to visit an optometrist who prescribed the right lens for my spectacles and I exclaimed, ‘wow, what a spectacular clear sight!’ I mean, the situation will not be that spectacular with a sample. Thus, with more numbers in the group the ‘middle box’ will shrink generally, unless we are ‘biased’. That’s another matter of interest in data analysis.
Anyway, I blamed me, as I could not make this anomaly of nature and life clearer to that student. Next time I will make it clearer that 'big variation' and 'big confidence' do not match most of the time.