Statistics

Question 1

Ith quartile

Answer 1

Li+(nxi/4 -cfb) w
      —————
              Fqi 
Li= lower class boundary of the quartile class
Nxi= position of the quartile class
Cfb= cumulative frequency before the quartile class
Fq= frequency of the quartile class 
W= class width

Question 2

Coefficient of variation

Answer 2

L1+[n/2-cfb] ce
————
Fm

Li= lower class boundary of the median class
N/2= position of the median class
Cfb= cumulative frequency before the median class
Fq= frequency of the median class 
W= class width

Question 3

Standard error refers to the

Answer 3

standard deviation of statistics

Question 4

Steps on how to solve for standard error

Answer 4

1. compute the standard deviation of the population values. in this case
   S/N X X - µ (X-µ)^2
   σ = √((x-µ)^2/N)
2. compute the standard deviation of the sampling distribution of means (without replacement)
3. multiply the standard deviation of the population by square root of (N-n)/(N-1) and divine by square root of n according to theorem 2
4. compare the result in step 3 with that of step 2. If they are the same, INDICATE and stop. If you stop without indicating, you’ll lose very valuable marks