September 16, 2013
Stat of the Week Competition: September 14 – 20 2013
Each week, we would like to invite readers of Stats Chat to submit nominations for our Stat of the Week competition and be in with the chance to win an iTunes voucher.
Here’s how it works:
- Anyone may add a comment on this post to nominate their Stat of the Week candidate before midday Friday September 20 2013.
- Statistics can be bad, exemplary or fascinating.
- The statistic must be in the NZ media during the period of September 14 – 20 2013 inclusive.
- Quote the statistic, when and where it was published and tell us why it should be our Stat of the Week.
Next Monday at midday we’ll announce the winner of this week’s Stat of the Week competition, and start a new one.
The fine print:
- Judging will be conducted by the blog moderator in liaison with staff at the Department of Statistics, The University of Auckland.
- The judges’ decision will be final.
- The judges can decide not to award a prize if they do not believe a suitable statistic has been posted in the preceeding week.
- Only the first nomination of any individual example of a statistic used in the NZ media will qualify for the competition.
- Individual posts on Stats Chat are just the opinions of their authors, who can criticise anyone who they feel deserves it, but the Stat of the Week award involves the Department of Statistics more officially. For that reason, we will not award Stat of the Week for a statistic coming from anyone at the University of Auckland outside the Statistics department. You can still nominate and discuss them, but the nomination won’t be eligible for the prize.
- Employees (other than student employees) of the Statistics department at the University of Auckland are not eligible to win.
- The person posting the winning entry will receive a $20 iTunes voucher.
- The blog moderator will contact the winner via their notified email address and advise the details of the $20 iTunes voucher to that same email address.
- The competition will commence Monday 8 August 2011 and continue until cancellation is notified on the blog.
Rachel Cunliffe is the co-director of CensusAtSchool and currently consults for the Department of Statistics. Her interests include statistical literacy, social media and blogging. See all posts by Rachel Cunliffe »
Statistic: That a 4% increase in student fees roughly equates to a $2500 increase.
Source: Dominion Post
Date: paper edition of 17 September
A 4% increase equating to $2500 suggests that student fees are currently $63500 per annum. One would have thought that, given the journalist identified the supposed dollar amount of the crease, the apparent size of the supposed 4% increase would have led to maths-checking before publication.
11 years ago
Statistic: The headline reads: Headline:
Coffee quaffers face increased death risk: study
In the article is the statistic:
‘… men who drink more than four cups a day are 56 per cent more likely to die and women have double the chance compared with moderate drinkers …’
Fortunately I was pre-armed with the More or Less BBC4 podcast:
which talks about the relative figure and the ability or otherwise to strip out other factors.
Source: NZHerald & BBC4 Podcast
Date: Sep 18, 2013
As a relatively big coffee drinker who tries to limit my intake only to allow me to sleep better, my interest was piqued. Fortunately I had already listened to the BBC4 podcast, More or Less: ‘Is coffee bad for you? 24 Aug 2013’
http://downloads.bbc.co.uk/podcasts/radio4/moreorless/moreorless_20130824-0600a.mp3
The More or Less podcast pointed to a Guardian article:
http://www.theguardian.com/lifeandstyle/2013/aug/15/coffee-drinkers-risk-death-rate
More or Less has the very important caveats of relative risk, ie increasing the risk from a very small number is still a very small number and secondly, the ability or otherwise to control for other factors. In the guardian quote is this:
The study found that those who drank larger amounts of coffee were more likely to smoke and had less healthy lungs and hearts.
Which leads me to believe that the original study is valuable but only as part of a body of evidence and the actual Herald article is space filler material only.
I will continue with my terrible addiction combined with my regular exercise, gym sessions, and outdoor adventuring!
11 years ago
Statistic: Under limit after 13 beers in 2 hours
Source: New Zealand Herald
Date: 19 September 2013
This statistic doesn’t ring true and defies common sense.
The article says that a police officer who drank 13 beers in two hours remained under the legal drink-driving limit of 80. That’s incredible and I don’t believe it.
If we consult the tables at http://www.moderation.org/bac/bac-men.shtml we see that if a heavy 109kg man drinks 12 beers then after 2 hours his BAC would be 148 or roughly twice the limit.
The story can only be true if the police officer is much heavier than 109kg (say twice that) or if the beer is low alcohol and in either case the story is dishonestly misleading.
11 years ago
Statistic: America’s Cup boat closing speeds
Source: New Zealand Herald
Date: During the America’s Cup
We can’t let the week end without mentioning the America’s Cup on StatsChat. So here goes.
In case you haven’t heard of it, the America’s Cup is an international mathematics competition held on water. In it two teams of mathematicians compete to optimise a quantity called VMG with various constraints applied. Pretty tricky optimisation at times because the other team is allowed to alter your constraints dynamically such as by preventing you from occupying certain parts of the course.
Anyway, I’ve seen a common error that commentators make – that of closing speeds. The American commentators have said when both boats were doing 40 knots that the closing speed was 80 knots. And the Herald has a couple of articles where they have say that boats doing 30 knots have a closing speed of 60 knots.
But the boats never head directly to each other so you can’t add the two speeds. Usually, downwind or upwind the boats are traveling at 90 degrees to each other. So we have to divide by sqrt(2).
So the true closing speeds for 40 knots and 30 knots are respectively 57 and 42 knots, not 80 and 60.
11 years ago