In a survey, several people were asked how

Makanja Mwinyi 2022-07-22

In a survey, several people were asked how many years it has been since they purchased a mattress. The results are shown in the table.

Years since last purchase     0    1    2    3    4     5    
Number of people339912122323171788

 

Evaluate the following (Express the answer in 2 decimal places):

a) Standard deviation (4 Marks)

 

 

b) Coefficient of variation (1 Mark)

 

 

c) Expected value of xx, that is E(x)E(x) (2 Marks)

 

 

d) Variance of xx, that is Var(x)Var(x) (3 Marks)

 

 

e) The probability of having bought a mattress in the last 3 years. (1 M

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