Quiz Questions on Hypothesis Testing and Confidence Intervals - Prof. Rituparna Sen, Quizzes of Statistics

Download Quiz Questions on Hypothesis Testing and Confidence Intervals - Prof. Rituparna Sen and more Quizzes Statistics in PDF only on Docsity! Name: ~~§tident ID Quiz3 Time: 20min. Show calculations on back. 1. (3 points) A manufacturer oflow-calorie snacks claims that the mean number of fat grams per serving is less than 0.5 grams. (a) In testing the claim, what conclusion would constitute a type I error? (b) In testing the claim, what conclusion would constitute a type II error? (c.).If you were relying on these snacks ..to fit your diet, which error wo.uld be a detriment to your We~gh~.. lOSS.plans? __ t:'\ Ii. I cL'(\.;[ ~. ~ e101M W ~ ~ l'r u .;0-H . IlJ 1. •5 ~ ~(t}'\.~~ u ::'/f~'S © ~~--tW--tf£ c1P..<-'rA l4 r ~;.rLa~ ® f\~'1 . 2. (4 points) A mail-order company claims that the standard deviation in the length of delivery times is less than 6.2 days. A random sample of 30 delivery times has a standard deviation of 5.1 days. Assume the population is normally distributed. Determine the rejection region and the standardized test statistic. Use .~ = 0.05. What do you conclude about the claim? .. ~ )Il.. \.4 \ O? £<2. dl--::. CV)~\) ;1- ~ 2~?< l- ~~ ::-/Cf' 62.2-S"'" t+,,-: 0< fJ '2-- p- ~ (G· 2) 'n / ?0/ 0( --- 5! ., ~j'-ee.tA QY\ ~cr'(frIt2s _ 1-'-< ('";(-> =Fo 8 4fHai.lui ~-NI <J)fi ~ "'j~ \h ~ ~ n-I::?-9 ~. ta ~ QA7, QN\~tQ i\) ~ ::: ~. \ .~ .~ o(cx.i lY), 3. (2 points) In problem 2, find a 95% confidence ~nterval for the variance of the length of delivery times. ~ L. (r-l LJ1-- r:-~ ~6-1) CS.!t Z ~.( ~--\)t it lt~'f 2.'). ,6- OLff- l~,~Cf1b'( 6~«41"' {}O 50 4. (2 points) Suppose you wish to estimate a binomial parameter p conect to within 0.04, with probability equal to 0.95. If you suspect that p is equal to 0.2 and you want to be certain that your sample is large enough, how large should n be? IJ)~ f 1(~)~ e 2- ) C8) ( I' Cfb)?-e \ 'n4 38t.r '\ b or ~. 0~S,