SupposeX1,...,X20are iidNor(μx,σ2),Y1,...,Y20are iid Nor(μy,σ2),and all of theX′isare independent of all of theY′is. Further suppose thatX¯¯¯¯=23,S2x=5184,Y¯¯¯¯=−11,and S2y=900.Find a 95% two-sided confidence interval on the ratio of the population variancesσ2x/σ2y

Asap! i'm not good math and i'm lost.

Yesterday, george drank 1 small bottle and 2 large bottles, for a total of 1,372 grams. the day before , he drank 1 small bottle and 1 large bottle, for the total of 858 grams. how many grams does each bottle hold?

As voters exit the polls, you ask a representative random sample of voters if they voted for a proposition. if the true percentage of voters who vote for the proposition is 63%, what is the probability that, in your sample, exactly 5 do not voted for the proposition before 2 voted for the proposition? the probability is