Biostatistics

EXERCISES 33
25.21 30.49 27.38
36.42 41.50 29.39
24.54 41.75 44.68
24.49 33.23 47.09
29.07 28.21 42.10
26.54 27.74 33.48
31.44 30.08
Source: Data provided courtesy
of A. Hoekema, D.D.S.
(a) Use these data to construct:
A frequency distribution
A relative frequency distribution
A cumulative frequency distribution
A cumulative relative frequency distribution
A histogram
A frequency polygon
(b) What percentage of the measurements are less than 30?
(c) What percentage of the measurements are between 40.0 and 49.99 inclusive?
(d) What percentage of the measurements are greater than 34.99?
(e) Describe these data with respect to symmetry and skewness as discussed in Exercise 2.3.1, part h.
(f) How many of the measurements are less than 40?
2.3.4 David Holben (A-4) studied selenium levels in beef raised in a low selenium region of the United
States. The goal of the study was to compare selenium levels in the region-raised beef to selenium
levels in cooked venison, squirrel, and beef from other regions of the United States. The data below
are the selenium levels calculated on a dry weight basis in mg=100 g for a sample of 53 region-raised
cattle.
11.23 15.82
29.63 27.74
20.42 22.35
10.12 34.78
39.91 35.09
32.66 32.60
38.38 37.03
36.21 27.00
16.39 44.20
27.44 13.09
17.29 33.03
56.20 9.69
28.94 32.45
20.11 37.38
25.35 34.91
21.77 27.99
31.62 22.36
32.63 22.68
30.31 26.52
46.16 46.01
(Continued )