Experiment!: Planning, Implementing and Interpreting

Further Reading

The contents of this chapter are described in most elementary textbooks on statistics. Many such books take a rather mathematical approach to the subject. It is often beneficial for the understanding to present statistical ideas and tools by practical examples. Statistics for Experimenters by Box, Hunter and Hunter [1] does so in a clear way and is probably one of the better statistics books available for people doing experimental work. Those readers who want to write programs for statistical analysis might consider Statistics – an introduction using R by Crawley [2]. “R” is a freely available language and environment for statistical computing and graphics. It is platform independent and can be downloaded at http://cran.r-project.org/.

ANSWERS FOR EXERCISES

7.1 Make a numbered list over all addresses in the nation. Draw the numbers using a random number generator, for example using the Excel function = RAND().

7.2 Mean = 7.22, median = 7, mode = 7.

7.3 Mean = 3, median = 3 for all three dot plots. The range is 0 in the top dot plot and 4 in the other two.

7.4 Standard deviation = 3.96.

7.5 See the answer for Exercise 8.9 and the discussion of these data in connection to the one-sample t-test in Chapter 8.

7.6 See the discussion of these data in connection to the two-sample t-test in Chapter 8.

7.7 Z= 1.61. The cumulative probability F(Z) = 0.9463 (read from the table of standard normal probabilities in the Appendix). The probability of finding a rate greater ...