Stat 427/527 HW 1: due Thursday September 8, 2005
  
  Directions: Do all calculations in MINITAB. Use a word processor of 
   your choice to write a report.  Insert computer text output and graphics 
   to support what you are saying, but you need to write something that looks
   like an academic paper - not a pile of computer output.

  1. The Dept of Meteorology at the University of Stockholm monitors chemical
  constituents of the atmosphere at several stations throughout Sweden.
  The chemicals are precipitated out of the atmosphere by rain and deposited
  on filters, from which the amount of chemical, in milligrams per 
  square meter of filter surface, can be measured. The amount of Sulfur (S)
  for each of the 12 months M (1=Jan, 2=Feb, etc) and the monthly precipitation
  (Precip) for one station is given in the table below.

         Month     Precip (mm)      S       
       ----------------------------------

           1         35            55
           2         25            30
           3         12            25
           4         36            43
           5         81           135
           6         19            38
           7         55            63
           8         63            93
           9         69            64
          10         23            17
          11         52            34
          12         35            34

        ----------------------------------


    a. Enter the Precip data into the Minitab worksheet.  Note: you can swipe
       the data above off of your web browser and copy it to the clipboard.  Then
       in MINITAB, click on the the first cell in the first collumn and choose
       EDIT > PASTE CELLS.  Stay with the default USE SPACES AS DELIMITERS.

    b. Make a stem and leaf display, histogram, and high-quality boxplot for the 
       Precip data. Make sure to specify the following options in the
       dialog box for the boxplot: IQRange Box, Median Symbol, Outlier 
       Symbol.
   
    c. Compute the mean, median, standard deviation, and interquartile
       range for the Precip data. Is there much difference between the
       mean and median? Discuss, briefly, whether the size and the direction
       of the difference is sensible, given the graphical summaries.

    d. Using the graphical summaries, describe the shape of the 
       Precip distribution. Discuss modality, presence/absence of outliers,
       whether skewness is present, and if so, in what direction, and 
       whether it would be reasonable to assume that the Precip 
       distribution is normal.  

  2. Repeat steps a-d for the following data:

     These data, from Holling (1982), are the body masses (in grams) for 
     36 species of boreal forest mammals found east of the Manitoba-Ontario 
     border in pure or mixed conifer strands:

          3.69
          4.11
          4.25
          5.24
          5.50
          8.36
         13.18
         22.45
         22.96
         24.52
         26.93
         28.30
         28.35
         33.00
         42.53
         43.94
         44.51
         80.80
        104.90
        191.36
        839.15
       1224.70
       1496.85
       2642.17
       3118.45
       8504.85
       9071.84
      10149.12
      12303.68
      14061.35
      23995.02
      43204.64
      86416.53
     105686.93
     169643.40
     481828.10

  3. Repeat steps a-d for the natural log of the data in problem 2.