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. Following are measurements of electrical conductivity (in microsiemens per centimeter) for 23 water samples.
|
tive frequency for a given class interval are the sums
|
2099
|
528
|
2030
|
1350
|
1018
|
384
|
1499
|
|
of the frequencies and relative frequencies, respec-
|
1265
|
375
|
424
|
789
|
810
|
522
|
513
|
|
tively, over all classes up to and including the given
|
488
|
200
|
215
|
486
|
257
|
557
|
260
|
|
class. For example, if there are five classes, with fre-
|
461
|
500
|
|
|
|
|
|
|
quencies 11, 7, 3, 14, and 5, the cumulative frequen-
|
|
|
|
|
|
|
|
cies would be 11, 18, 21, 35, and 40, and the cumulative relative frequencies would be 0.275, 0.450,
a. Find the mean.
b. Find the standard deviation.
c. Find the median.
d. Construct a dotplot.
e. Find the first quartile.
f. Find the third quartile.
g. Find the interquartile range.
h. Construct a boxplot.
i. Which of the points, if any, are outliers?
j. If a histogram were constructed, would it be skewed to the left, skewed to the right, or approximately symmetric?