The following is the record of ratings of 40 players in a tournament.

 65    85   91   58   43   86

73    33   76   80   57   33

53    29   40   27   72   19

51    67    37    4   18     92

13    45    61  39   23     22

22    41     27  51   63    47

19    35     39  72 

 

a. Find the number of classes or intervals required and the class width.

b. Construct a frequency distribution table using the classes determined in (a).

c. Draw a cumulative frequency curve and use it to find the median and the upper and lower quartiles.

d. Draw a histogram and use it to estimate the mode and the median.