Next:Exercise 1.6Up:No TitlePrevious:Exercise 1.4

# Exercise 1.5

1.
Use the summary module to obtain these statistics for the two data sets in #1, Exercise 1.4. Using these statistics, obtain comparison boxplots of the two samples.
2.
Check the robustness of the statistics in the descriptive statistics command on the following two data sets using the summary module.

Data1  Data2
102   1020
131    131
137    137
63     63
42     42
12     12
23     23
49     49
63     63
21     21
56     56
68     68
35     35
63     63
62     62
19     19
85     85
38     38
76     76
29     29
31     31
16     16
0      0
8      8
47     47
40     40
2      2
44     44
8      8
16     16
7      7
43     43
2      2
50     50
22     22
1      1
51     51
34     34
4      4
78     78

Notice that in the second data set,the 102 was changed to 1020. Which statistics were robust to this change? Which weren't?

3.
Same as the last exercise but change the 1020 to 10200.
4.
Same as the last exercise but change the 10200 to 102000.
5.
Did Manuel I shortchange the people by having less silver in in later days mintings? Try to answer this question by comparing the following two data sets (use comparison boxplots). The first data set is the amount of silver (percentage)in Manuel's first minting while the second data set is the amount of silver (percentage) in Manuel's fourth minting.

Silver Minting
5.9        1
6.8        1
6.4        1
7.0        1
6.6        1
7.7        1
7.2        1
6.9        1
6.2        1
5.3        4
5.6        4
5.5        4
5.1        4
6.2        4
5.8        4
5.8        4

6.
Using the LDL levels of quail a drug compound (call it A) was put on test. In the experiment, 30 quail were randomly chosen and 20 were assigned to a placebo and the other 10 to the treatment using Drug A. The drug was mixed in their food. Other than this, though, the quail were treated the same. At the end of the treament period, the Low Density Lipid levels of the quail were measured and are given below. Here smaller is definitely better. The data are real.(drug=0 for placebo and drug=1 for drug A)
LDL drug
64    0
49    0
54    0
64    0
97    0
66    0
76    0
44    0
71    0
89    0
70    0
72    0
71    0
55    0
60    0
62    0
46    0
77    0
86    0
71    0
40    1
31    1
50    1
48    1
152    1
44    1
74    1
38    1
81    1
64    1
(a)
Obtain comparison dot plots of the data and try to decide if the drug A was effective.
(b)
Obtain the descriptive statistics for each data sets. Which (difference in means, difference in medians, difference in HL) seem more appropriate here? Why?

Next:Exercise 1.6Up:No TitlePrevious:Exercise 1.4
2000-08-26