INDIAN SCHOOL MUSCAT 
                                                                          Statistics for Economics 
                   Class : 11                Worksheet on Simple Arithmetic Mean                                                   Reference: 
                                                               and Weighted Mean                                             NCERT text book 
                Date of issue                                    Worksheet No. 05                                            Date of submission 
              --------------2018                                   Economics (030)                                           ------------------2018 
                           
          Very short answer type questions 
           
               1.  Define a measure of central tendency. 
               2.  Mention the formula for calculation of mean in ungrouped data, grouped data of discrete and class 
                    individual series. 
               3.  Define arithmetic mean. 
               4.  What is the difference between simple arithmetic mean and weighted mean? 
               5.  Give one important property of arithmetic mean. 
               6.  State any two advantages of arithmetic mean. 
               7.  State any two disadvantages of arithmetic mean. 
               8.  State any one difference between mean and median. 
                     
          Numerical Questions 
               1.  Calculate mean from the following. 
                    18, 20, 25, 17, 9, 11, 23, 37, 38, 42, 36, 35, 8, 6, 11, 21, 20, 41, 35 
                     
               2.  Calculate mean from the following. 
                                        Size                      3         6         9        12        15        18        21 
                                        Frequency                 3         6         8        10         9        2         1 
           
               3.  Calculate Arithmetic mean from the following. 
                                        Class                    5 – 15       15 – 25       25 – 35       35 – 45       45 – 55 
                                        Frequency                   4            10            18            6             2 
                     
               4.  Calculate Mean. 
                                 Marks less than              10        20        30        40        50        60        70       80 
                                 Number of students            4        10        18        30        42        50        56       60 
                     
               5.  Calculate Mean. 
                                       Marks more than           10          20          30          40          50          60 
                                       Frequency                 50          46          40          30          18          7 
                     
               6.  The following information shows the number of different books sold by the book store of the school. 
                    Calculate weighted mean. Consider the number sold as weight  
                          Books               Statistics              Physics              Economics              commerce            Chemistry 
                                                                                                  
                     Number Sold                  40                     25                     12                     13                 10