Answers to exercises in Sect. 37.18.

Answer to Exercise 37.1: The graph: odd colour choice; vertical axis label isn’t helpful; horizontal axis isn’t labelled at all; units of measurement not given.; title and/or caption would be helpful.

The table: the two limits of the CI are under the Mean and Std dev columns, but that is not what they are; units of measurement are not given; no caption, or any way to know what the table is about; number of decimal places is inconsistent. sample sizes not given; difference, and probably the other rows too, should report a standard error.

Answer to Exercise 37.2: RQ: P, O, C and I are not clear or explicit; the two fonts being compared should be identified. Perhaps better: ‘For students, is the mean reading speed for text in the Georgia font the same as for text in Calibri font?’

Abstract: statement poorly constructed (fonts are not fast or slow!). Perhaps: ’The sample provided evidence that the mean reading speeds were different ($$P=???$$), when comparing text in Georgia font (mean: ???) and Calibri font (mean: ???; 95% CI for the difference: ??? to ???).

Answer to Exercise 37.3: No units of measurement given (they are centimetres.); jump-heights are given to 0.001 of a centimetre… which seems rather optimistic; table gives information for the differences, which is great but it could also provide numerical summary information for each individual jump type too; a numerical summary shouldn’t include a $$P$$-value, $$t$$-score, or confidence interval.
Answer to Exercise 37.4: Variables are qualitative, so means inappropriate; the appropriate summary is an odds ratio, so the values almost certainly refer to the CI for the OR. Without more information, we can’t really be sure what the OR means though.
Answer to Exercise 37.5: Such a study cannot prove anything just by itself (only a sample studied); the two CIs for the hang time for each plane design is fine… but really, the difference is of interest: The appropriate CI is for the difference between the mean hang times.
Answer to Exercise 37.6: 1. Table: Reasonably good! 2. Figure: Poor (it is 3D). Use a stacked or side-by-side bar chart.
Answer to Exercise 37.7: Reasonably good: should not be gaps between the bars of the histogram.