Issue 7 - February 2001 |
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The three experiments were conducted by a total of 1,005 pupils in the UK (694 in primary schools, 311 in secondary schools)
To find out if this 12 per cent difference is statistically significant, we can calculate its "p-value" - that is, the chances of getting at least as big a difference as that observed just by fluke. This probability turns out to be extremely low (p ~ 10-127) Thus the 62 per cent rate is both substantially, and statistically significantly, different from the rate expected by chance alone.
Results
Again, statistical significance tests against the null hypothesis of a 50:50 split gives an extremely low p-value (~ 10-57). Toast with just a "B" on it thus still lands face-down at a rate substantially, and statistically significantly, different from value expected by chance alone.
Results
Both these differences are statistically significant (p = 0.003 and 10-37 respectively). So increasing drop height to 2.5 metres gives a substantially and statistically significantly higher probability of producing a butter-up landing.
- Toast really does have a tendency to land butter-side down.
- The presence of butter is not the major cause of butter-side down landings.
- The principal cause is height: toast falling from waist-height does not have enough time to come butter-side up again.
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