CHI square vs F-Test

[kansal7mba]

What is the difference between F-test and CHI square test? They look similar.
Also how do we decide when to use a 1 or 2 tail values in tables?

 

[ShaktiRathore]

F-test is used to compare two samples variances and conclude whether they are drawn from the same population.F=s1^2/s2^2,s1>s2.
Chi test is used to test whether the population variance is equal to a hypothesied value.Ch- stat=(n-1)*s^2/sigma^2.
thanks

 

[kansal7mba]

Thanks Shakti.