(Answered) : Question 3 20 Marks Use Formulae Provided Answer Questions Follow Y Bx B X Nb X Mean X Mea Q28382197

Question 3 [20 marks]
Use formulae provided to answer the questions that follow
y= a +bx where a= ? –b-x (NB; -x=mean of x and ? is mean ofy)
Executive Masters Assignment Two
January – June RM322 Research Methods
© BOU 2018 Page 3 of 4
b= ?x–x)(y-?)
?(x–x)2
r=?(x–x)(y-?)
??(x–x)2(y-?)2
The table below shows results from a randomly selected sample ofpolice officers
who sat for a promotion test. The station management wanted toestablish if the test
performance varied with length of service of the particularofficer.
Officer Service period in
years
Score on
Promotion test %
1 9 60
2 8 70
3 3 55
4 9 60
5 10 70
6 5 50
7 7 60
8 4 55
a. Formulate the null and