{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

# 420Hw03 - STAT 420 Homework#3(due Friday February 8 by 4:00...

This preview shows pages 1–2. Sign up to view the full content.

STAT 420 Spring 2008 Homework #3 (due Friday, February 8, by 4:00 p.m.) 1. An employee claims that drinking beer has no effect on the amount of time it takes for him to perform a particular task. The following data show how many seconds he took to perform the task after consuming various quantities of beer, measured in ounces: Beer Consumption, x Time, y 0 62 12 50 24 59 36 74 48 59 60 83 72 68 Σ x = 252, Σ y = 455, Σ x 2 = 13,104, Σ y 2 = 30,295, Σ x y = 17,388, Σ ( x x ) 2 = 4032, Σ ( y y ) 2 = 720, Σ ( x x ) ( y y ) = Σ ( x x ) y = 1,008. Consider the model Y i = β 0 + β 1 x i + ε i ., where ε i ’s are i.i.d. N ( 0, σ 2 ) . a) Find the equation of the least-squares regression line. b) Give an estimate for σ , the standard deviation of the observations about the true regression line? c) What proportion of observed variation in time needed to perform the task is explained by a straight-line relationship with the amount of beer consumed? d) How much time would you expect the employee to need to perform the task after consuming 144 ounces of beer.

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
1. (continued) e) The company statistician said that the prediction obtained in part (d) should be
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

### What students are saying

• As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

Kiran Temple University Fox School of Business ‘17, Course Hero Intern

• I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

Dana University of Pennsylvania ‘17, Course Hero Intern

• The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

Jill Tulane University ‘16, Course Hero Intern