Work through the list without notes. If you cannot do a statement, follow its link, then come back. Guide = study guide; Practice = practice questions.
Understanding
- I can explain the difference between a measure of centre and a measure of variability. (Guide: “Why summarise a distribution with numbers?”)
- I can explain what a standard deviation tells me as a typical distance from the mean, and why it is not a maximum distance. (Guide: Worked example 1; Practice Q7)
- I can say which statistics are resistant (median, IQR) and which are not (mean, range, s), and explain why. (Guide: “Resistant and non-resistant statistics”; Practice Q2)
- I can predict how multiplying the data by a constant, or adding a constant, changes each statistic. (Guide: “Changing the units”; Practice Q3)
Skills
- I can find the median and quartiles of a data set with an odd or even number of values. (Guide: “Measures of position”; Practice Q1)
- I can find the percentile of a given value. (Guide: “Measures of position”; Practice Q7)
- I can calculate the range and IQR and interpret the IQR as the spread of the middle half. (Practice Q1, Q5)
- I can calculate the sample standard deviation by hand, dividing by n − 1, and check it with Sx on a calculator. (Guide: Worked example 1; Practice Q4)
- I can apply the 1.5 × IQR rule and the 2-standard-deviation rule to flag potential outliers. (Guide: Worked example 2; Practice Q5, Q6)
Reasoning
- I can justify whether the mean or the median better describes a typical value, using the shape and any outliers. (Guide: Worked example 2; Practice Q5)
- I can compare two distributions using summary statistics, with comparative words, values and units. (Practice Q6)
- I can write every interpretation in context, naming the variable, the individuals and the units. (All worked examples)
All ticked? Move on to Topic 1.8, Graphical Representations of Summary Statistics for One Quantitative Variable, or return to the course roadmap.