The article "Hydrogeochemical Characteristics of Groundwater in a Mid-Western Coastal Aquifer System" (S. Jeen, J. Kim, et al., Geosciences Journal, 2001:339-348] presents measurements of various properties of shallow groundwater in a certain aquifer system in Korea. The measurements of electrical conductivity (in microsiemens per centimeter) for 23 water samples are provided in the table below. Use these values to calculate the following "by hand". Hand calculations may be aided with the use of spreadsheets or software like Excel as long as the only functions used are sort, sum, product, difference, square, squareroot and all intermediate output is included in your answer. a. Calculate the mean by hand.
b. Interpret the mean.
c. Calculate the variance by hand.
if necessary.
d. Calculate the standard deviation using the work already done for the variance. if necessary.
e. Interpret the standard deviation.
f. Find the median. You must show your work.
g. How do the mean and median compare? What does it tell you about the distribution?
h. Find the quartiles of the data set. You must either show your work.
i. Calculate the interquartile range (IQR). Please be sure to show your work.
j. Determine if this data set contains any outliers. Please be sure to show your work and to explain your conclusion.
k. Construct the outlier boxplot by hand.
l. What does the outlier boxplot tell you about the shape of the distribution?