For instance:
  • In  the  pharmaceutical  industry.  It  is  impossible  to 
   test every drug for every person that may require it. 
   So the industry needs a statistician. 
  • In business, managers must often decide whom to 
   offer  their  company’s  products  to  such  as  a  credit 
   card  company  must  asses  how  risky  a  potential 
   customer is. 
  • An  individual  who  needs  to  lose  weight  for  his 
   upcoming  new  film.  He  needs  to  see  data  of 
   successful diet.
             Average weight loss on Various diets across 8 weeks
                                                 Weight
             Diet       1         2        3        4         5        6        7         8
            Diet 1   310       310      304      300       290      285      280       284
            Diet 2   310       312      308      304       300      295      290       289
            Diet 3   310       307      306      303       301      299      297       295
            Diet 4   310       308      305      303       297      294      290       287
                       Based on these numbers, which 
                         diet should he/she  addopt?
       two types of statistics
       •   Descriptive statistics: utilize numerical and graphical method to look for 
           patterns in a data set, to summarize information revealed in a data set, 
           and to present the information in a convenient form that individuals can 
           use to make decisions. The main goal of descriptive statistics is to describe 
           a  data  set.  The  class  of  descriptive  statistics  include  both  numerical 
           measures (e.g. Mean, Median) or graphical displays of data (e.g. Charts or 
           graphs)
       •   Inferential  statistics:  utilize  sample  data  to  make  estimates,  decisions, 
           predictions, or other generalizations about a larger set of data. 
      descriptive statistics
      •  Look at example of the table of various diets
      •  What informations provided by the table?
      The most significance of diet process is Diet 1
      Furthermore, Diet 1 is not stable (see week 7 & 8)
      Diet 4 shows a steady decline in weight loss
      One can make an educated decision suitable for his/her 
         personal weight loss goals. 
       inferential statistics
       •    The main goal is to make a conslusion about a population based on a sample of a 
            population. 
       •    Inferential statistics mostly uses hypethesis testing. 
       •    Key Definition:
       •    Experimental unit (an object upon which data is colletced)
       •    Population (a set of units that is of interest to study)
       •    Variable (a characteristic or property of an individual experimental unit)
       •    Sample (a subset of the units of a population)