Page 175 - Data Science class 10
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8.  The relationship between engine displacement and fuel economy is a ____________.
                  a.  curved line                                    b.  scattered points

                  c.  straight line                                  d.  None of these

               9.  The central limit theorem states that sampling distribution of the sample mean is approximately normal if ____________.
                  a.  all possible samples are selected
                  b.  the sample size is large

                  c.  the standard error of the sampling distribution is small
                  d.  All of the above

              10.  The main cause of stakeholders being frequently shocked by real facts is ____________.
                  a.  linearity bias                                 b.  sampling
                  c.  hypothesis                                     d.  Both a and b


            B.  State whether these statements are true or false.
               1.  Selection bias cannot bias the estimates of parameters of the statistical model.           ________

               2.  Making a graph is the easiest (and most effective) way to demonstrate the impacts of linearity bias.   ________

               3.  Prime numbers are the numbers that have factors as 1 and that number itself.               ________
               4.  The information obtained from the statistical sample doesn’t allow statisticians to create hypotheses
                  about the wider population.                                                                 ________

               5.  Sampling errors occur because no sample will ever perfectly match the data from which the sample is taken.  ________

               6.  A good representation is one that doesn’t make use of discriminating attributes.           ________

               7.  Subjective writing expresses opinions and feelings rather than facts.                      ________
               8.  Partiality is tendency to favour fairly.                                                   ________

               9.  Psychology, economics, and philosophy use the word preference to choose between alternatives.   ________

              10.  Recall bias are also known as survivorship bias.                                           ________


                 Standard Questions (Section B)


            A.  Short answer type questions:
               1.  Explain what is Bias and why it occurs in data science?                           [CBSE Handbook]

             Ans.  The partiality, preference and prejudice towards a set of data is called as a Bias. Data bias leads to biased models, which
                  may be unfair and harmful to people. A thorough evaluation of the available data and its processing to mitigate biases
                  should be a key step in modelling.
               2.  How will you explain Central Limit Theorem?
             Ans.  The Central Limit Theorem is a statistical theory stating that given a significantly large sample size from a population
                  with finite variance all samples taken from the same population will have a mean that is nearly equal to the population
                  mean. This holds true regardless of whether the source population is normal or skewed provided that the sample size
                  is significantly large.




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