Statistics and Data Analysis for Microarrays Using R and Bioconductor, 2nd Edition

212 Statistics and Data Analysis for Microarrays Using R and Bioconductor

There are a few interesting phenomena that are relevant to the mean as a

measure of central tendency. Let us consider the following set of measurements

for a given population: 55.20 , 18.06, 28.16, 44.14, 61.61, 4.88, 180.29, 3 99.11,

97.47, 56.89, 271.95, 365.29, 807.80, 9.98, 82.73.

The population mean can be computed as:

µ =

P

15

i=1

X

i

15

=

55.20 + 18.06 + 28.16 + ···+ 82.73

15

= 165.570 (8.4)

Let us now consider two samples from this population. The first sample is

constructed by picking the fir st four measurements in the population: 55.20 ,

18.06, 28.16, 44.14 and has the mean 36