The U.S Energy Information Administration collects data on

The U.S Energy Information Administration collects data on residential energy consumption and expenditures. Results are published in the document Residential Energy Consumption Survey: Consumption and Expenditures. The following table gives one year’s energy consumptions for a sample of 50 households in the South. Data are in millions of BTUs.

130   55   45   64   155   66   60   80   102   62

58     101 75   111 151   139   81   55   66    90

97    77   51    67   125   50   136   55   83    91

54   86   100   78   93    113   111 104   96   113

96   87   129   109 69    94    99    97   83   97

(a). Obtain a normal probability plot of the above data.

(b). Determine if the variable under consideration is approximately normal or not? (Use the 70% cut-off Rule)

(c). Obtain the five – number summary from the graphical display of the above data.

(d). Use the 1.5IQR Rule to determine any outlier(s).