Introductory Biostatistics
equal, the shape of the histogram looks similar to the graph, with relative fre- quencies on the vertical axis. To draw afrequen ...
an apparent bimodal distribution; however, a closer examination shows that among the nine patients with over 100% saturation, ei ...
Example 2.5 The distribution of family income for the United States in 1983 by race is shown in Table 2.5. The distribution for ...
2.1.4 Cumulative Frequency Graph and Percentiles Cumulative relative frequency,orcumulative percentage, gives the percentage of ...
graph, they provide a rapid visual comparison without any need to compare individual intervals. Figure 2.7 gives such a comparis ...
called themedian. In Figure 2.7 the median family income in 1983 for non- whites was about $17,500, compared to a median of abou ...
measured by the American standard. However, the pattern changes by the age of 15 years when their average height drops to a leve ...
children at a day-care center are as follows: 68 63 42 27 30 36 28 32 79 27 22 23 24 25 44 65 43 25 74 51 36 42 28 31 28 25 45 1 ...
calledleaves. There are no hard rules about how to construct a stem-and-leaf diagram. Generally, it consists of the following st ...
we are now able to define a number of important summarized measures, start- ing with the arithmetic average ormean. 2.2.1 Mean G ...
intervals are 10–19 20–29 30–39 the midpoint for the first interval is 9 : 5 þ 19 : 5 2 ¼ 14 : 5 and for the second interval is ...
skewed distributions, analyses are commonly done on the log scale. After obtaining a mean on the log scale, we should take the a ...
The remission times of 42 patients with acute leukemia were reported from a clinical trial undertaken to assess the ability of t ...
groups. However, the mean can be so expressed. If component groups are of sizesn 1 andn 2 and have meansx 1 andx 2 respectively, ...
It would be no use to take the mean of deviations because X ðxxÞ¼ 0 Taking the mean of the absolute values, for example P jxx ...
and errors arise in the subtraction of this figure from eachx. This di‰culty can easily be overcome by using the following short ...
sent the amount of information contained in the sample. The real explanation forn1 is hard to present at the level of this book ...
distribution symmetry. If they are approximately equal, the data set is roughly symmetric; otherwise, we are able to see the deg ...
a measure of location, atypicalvalue representing the data set. In addition, the varianceand/orstandard deviationis formed and u ...
In other words, the statisticpð 1 pÞcan be used in place ofs^2 as a measure of variation; the logic can be seen as follows. Fir ...
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