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Ans.   Class   m=(11+12)/2      F        fm        cf
                           0-10         5          16        80       16
                          10-20        15           8       120       24
                          20-30        25          35       875       59
                          30-40        35          36      1260       95
                          40-50        45           5       225      100
                          Total        125        100      2560
                                    Mean =  2560    = 25.6
                                            100
                                                   th
                                    N/2 = 100/2 = 50  item which lies in class 20-30 (as per cf)
                                                 50 – 24
                                    Median = 20+   35   x 10

                                    =20+7.4 = 27.4
                   Modal class = 20 – 30 (as per grouping Analysis)
                                 35 – 8
                   Mode = 20 +           x 10
                               2(35)–8–36
                   = 20+10.38 = 30.38

                   5.   Describe the different types of joins with diagrams.

                   Ans.  There are four types of joins:
                       •     Inner Join:  Those records are selected that have matching values in both tables. In an inner join, only those
                           tuples that satisfy the matching condition are included, while the remaining tuples are excluded.
                              Syntax: SELECT table1.column1, table1.column2, table2.column1, ....
                              FROM table1
                              INNER JOIN table2

                              ON table1.matching_column = table2.matching_column;
                              where table1: First table, table2: Second table and matching_column: Column common to both the tables.
                   •   Left Outer Join: This join returns all records from the left table, and the matching records from the right table.
                       Syntax: SELECT table1.column1,table1.column2,table2.column1,....

                       FROM table1
                       LEFT JOIN table2
                       ON table1.matching_column = table2.matching_column;
                   •   Right Outer Join: It returns all records from the right table, and the matching records from the left table.
                       Syntax: SELECT table1.column1,table1.column2,table2.column1,....

                       FROM table1
                       RIGHT JOIN table2
                       ON table1.matching_column = table2.matching_column;
                   •   Full Outer Join: Combines the result of both LEFT JOIN and RIGHT JOIN. It returns all records which match in either
                       left or right table.
                       Syntax: SELECT table1.column1,table1.column2,table2.column1,....
                   FROM table1

                   FULL JOIN table2
                   ON table1.matching_column = table2.matching_column;

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