Page 247 - Data Science class 11
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6.  Many quantitative analysts use R as their ______________________ tool.
                  a.  Leading tool                                   b.  Programming tool

                  c.  Both a and b                                   d.  None of these
               7.  Descriptive analysis tells us about ______________________.
                  a.  Past                                           b.  Present

                  c.  Future                                         d.  All of these
               8.  Which of the following sorts the dataframe by the order of the elements in B?
                  a.  x[rev(order(x$B)),]                            b.  x[ordersort(x$B),]

                  c.  x[order(x$B),]                                 d.  None of these
               9   A matrix is ______________________dimensionsinal rectangular data set.
                  a.  5                                              b.  4

                  c.  3                                              d.  2
               10.  The ______________________ function takes a vector or other object and splits it into groups determined by a factor or list
                  of factors.
                  a.  apply()                                        b.  split()

                  c.  isplit()                                       d.  mapply()

              11.  ______________________ applies a function over the margins of an array.
                  a.  apply()                                        b.  lapply()
                  c.  tapply()                                       d.  mapply()

               12.  Data frames can be converted to a matrix by calling data ______________________.
                  a.  matr()                                         b.  mat()
                  c.  matrix()                                       d.  None of these

               13.  Which of the following methods makes a vector of repeated values?
                  a.  rep()                                          b.  data()
                  c.  view()                                         d.  None of these
               14.  R objects can have attributes that are like ______________________ for the object.

                  a.  metadata                                       b.  features
                  c.  expressions                                    d.  All of these
               15.  Attributes of an object (if any) can be accessed using the ______________________ function.

                  a.  objects()                                      b.  attrib()
                  c.  attributes()                                   d.  All of these
              16.  ______________________ involves predicting a response with meaningful magnitude, such as quantity sold, stock price, or
                  return on investment.
                  a.  Regression                                     b.  Clustering

                  c.  Summarization                                  d.  None of these
              17.  ______________________ provides needed string operators in R.

                  a.  str                                            b.  forcast
                  c.  stringr                                        d.  None of these


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