A water plant’s peak power demand (KWH) each year as shown in the table:

Date P (KWH) Date P (KWH) Date P (KWH) Date P (KWH) Date P (KWH)

1986 248 1992 254 1998 725 2004 215 2010 248

1987 359 1993 596 1999 548 2005 548 2011 843

1988 154 1994 357 2000 921 2006 265 2012 845

1989 856 1995 248 2001 325 2007 157 2013 365

1990 92 1996 368 2002 365 2008 920 2014 282

1991 487 1997 954 2003 219 2009 215 2015 204

Analyze this data set and discuss the following:

Raw Data Assessment

(a) Were there any outliers that you discarded? Which ones & Why

(b) Is there a trend to this data?

(c) What is the mean, median, and mode of this data set? Ans: Mean = 439, Median = 358, Mode = 248

(d) What is its standard deviation of this data set? What are the upper and lower values of 67% range of the flows and how do these compare to the upper and lower values of the full range of data? Ans: Std.Dev = 264, Range 176 – 703

(e) What is its Skewness, Standard Error of Skewness, and acceptability of the skewness of this data set? Ans: Skedness 0.80, ses = 0.45

(f) What is its Kurtosis, Standard Error of Kurtosis, and acceptability of the Kurtosis of this data set? Ans: Kertosis = -0.77, sek = 0.89

(g) Can a standard (Gaussian) distribution be used to describe this data set?