Class Notes (807,339)
Canada (492,708)
Administration (2,629)
ADM2304 (69)
Tony Quon (67)
Lecture 3

ADM2304 Lecture 3: 3

4 Pages
Unlock Document

University of Ottawa
Tony Quon

> A 100(1) C.I. for , when SD is unknown: > where t 2,n1s the tvalue with n 1 degrees of freedom for which there is 2 probability in the right tail. We have replaced by s and the zvalue by a tvalue > If is unknown and n is large, then we can approximate the 100(1) condence interval for the population mean by Assumptions: a. Random sample not a convenience sample b. For small samples, the underlying population must be normally distributed. Why? c. For larger samples, the underlying distribution is not important. Sample Proportion: > Since the sample proportion has a known sampling distribution namely it is approximately normal with mean p and standard deviation squrt (p(1p)n) provided n is large enough! > Therefore, an approximate 100(1) C.I. for p has the form: e.g, Of 56 students polled, 10 found the midterm easier than expected and 46 found it harder than expected. Compute a 95 condence interval around the proportion of students who found the midterm easier than expected 10 p = 56=.18 > the value for z in this case is 1.96 (since 95) check assumptions:np =10.08 >10,n(1 p) = 45.92 >10 95C.I.for the truepopulationproportionof of allstudents whofound themidterm easier than expectedis (.18 .82 .181.96 56 = .08,.28 Go back to Margin of Error: > Suppose you want to insure that your estimate is within E of the true population proportion > but we dont know the sample proportion until we take the sample! So, either use a previous estimate of the proportion OR Chose the proportion that would makes the required n the largest Option 1: A Previous Estimate > If there exists a previous estimate for the proportion that can be used to determine the appropriate n
More Less

Related notes for ADM2304

Log In


Don't have an account?

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.