The following data gives the pH in rain/sleet/snow for 2004-05 at 20 rural sites on the US west 

coast. 

5.335

5.345

5.395

5.305

5.315

5.38

5.52

5.19

5.455

5.33

5.36

6.285

5.35

5.125

5.115

5.51

5.34

5.34

5.305

5.265

(a)  Create boxplot or histogram for this data and comment on whether sample mean or sample 

median be a better descriptor of a typical pH value.

(b)  Create a QQ-plot to check if normality assumption is appropriate for these data.

(c)   What test will you suggest to test whether a typical pH value is 5.4 or not? Conduct the test 

and conclude.