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Re: At the end of each year, the Harcar Corporation assigns a rating to ea
[#permalink]
18 Jun 2020, 20:32
2010 : graph is higher than other 2 graphs in ratings ( -3,-2,-1,1,2) and at 2nd top ( 0 and 3)
It means staff members were not lowest in 2010 by summing up all staff members
>>REFUTES
2011( lowest in all ratings in graph)
We don’t know if only few staff members in 2011 with higher rating could have high revenue that could be higher than overall sum of stff members with ratings over other years
>> Nor supports neither refute
Approach2:
Case1:
Say staff sales numbers= 10,20,30,40,50,60,70$; mean= 40
Standard deviation = sqrt (30)^2 + 20^2+10^2+0 +10^2+20^2+30^2)/7= 20
Rating 3= (individual total ( 70)- 40(mean))/(20) = 1.5
Rating2: 60-40/20 = 1
Rating1= 0.5
Rating0 = 0
Rating -1= -0.5
Rating -2= -1
Rating -3= -1.5
Case2:
Above ratings could be achieved if we choose the numbers
100,200,300,400,500,600,700$; mean= 400
Standard deviation = 200
Rating 3= (individual total ( 700)- 400(mean))/(200) = 1.5
If we need to calculate for different years, without any individual sales figure we can not determine total sales
>> Nor supports neither refute