Answers for all ‘Test Yourself’ questions from the book to check your performance and widen your overall understanding of the contents.

1. This data is positively skewed; the tail leads off to the right.
2. a)  Negatively skewed
   b) 21
   c) 4
   d) 3
3. This could be pronounced in many ways.  You might have picked any one of these, but they are all correct: “z is a deviation divided by the sample standard deviation” or “z is the difference between a score and the sample mean, divided by the sample standard deviation” or “z equals x minus x bar, all over s”.
4. a) Ratio, Mean
   b) Nominal, Mode
   c) Ordinal, Median
5. a) 5
   b) 5
   c) 6.67
   d) 2.58
6. There are many ways to do this, but here are some possibilities:
   “The centre of this dataset is 3.”
   “The distance between the highest and lowest value is 20”