In 2002, the median pH level of the rain in Glacier National Park, Montana, was 5.25. A biologist thinks that the acidity of rain has decreased since then. (This would mean that the pH level of the rain has increased.) She obtains a random sample of 15 rain dates in 2011 and obtains the following data:

Test the hypothesis that the median pH level has increased from 5.25 at the a = 0.05 level of significance.

Transcribed Image Text:

5.31 5.19 5.27 5.19 5.26 5.36 5.55 5.29 5.22 5.38 5.27 5.28 5.37 5.19 5.24