The statistics spreadsheet was produced by Jeremy Airey and downloaded from the OCC.
Quizstar QuizzesYou will need to register - no personal details such as email addresses are required and it is free. You will need to search for my quizzes either by title "Statistics for Biology" or under class search "Mr Mann's IB Biologists". The test consists of 10 multi-choice questions.
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Bozeman videoThis video is produced for AP (Advanced Placement in the US) but is just about spot on for IB Diploma Biology. Paul Anderson under the name "bozemanbiology" has many other videos worth viewing.
Re: exercise with 36 diceThe degrees of freedom are 5, as stated by Paul Anderson. There are six possible outcomes (n). The degrees of freedom = n-1, which in this case is 6-1 = 5. If every face of each dice had six dots on every face, there would be zero degrees of freedom, i.e. no other possible outcomes. However with six faces, each with a different number of dots, there are five alternative outcomes to the result.
Using Graphpad online software: "P value and statistical significance: Chi squared equals 9.667 with 5 degrees of freedom. The two-tailed P value equals 0.0853 By conventional criteria, this difference is considered to be not quite statistically significant. The P value answers this question: If the theory that generated the expected values were correct, what is the probability of observing such a large discrepancy (or larger) between observed and expected values? A small P value is evidence that the data are not sampled from the distribution you expected." http://graphpad.com/quickcalcs/chisquared2/ If the chi-squared value had been greater than the critical value of 11.07, it would have suggested that (at least some of) the dice had been weighted! The observed results would have been significantly different (p=0.05) to those expected. | ||||||||||||||
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