Exam 16: Simple Linear Regression and Correlation

A confidence interval (as opposed to a prediction interval)is used to estimate the long-run average value of y.

Telemarketing Sales and Experience The general manager of a telemarketing company believes that experience is the most important factor in determining the level of success of a telemarketer.To examine this belief she records last month's sales (in $1,000s)and the years of experience of 10 randomly selected telemarketers.These data are listed below. ​ ​ -{Telemarketer Sales and Experience Narrative} Compute the standardized residuals.

You cannot interpret the ____________________ of the simple linear regression line unless the value of x = 0 lies within the range of where data was collected.

The smallest value that the standard error of estimate sε can assume is:

Telemarketing Sales and Experience The general manager of a telemarketing company believes that experience is the most important factor in determining the level of success of a telemarketer.To examine this belief she records last month's sales (in $1,000s)and the years of experience of 10 randomly selected telemarketers.These data are listed below. ​ ​ -{Telemarketer Sales and Experience Narrative} Use the predicted and actual values of y to calculate the residuals.

Game Winnings & Education An ardent fan of television game shows has observed that,in general,the more educated the contestant,the less money he or she wins.To test her belief she gathers data about the last eight winners of her favorite game show.She records their winnings in dollars and the number of years of education.The results are as follows. ​ ​ -{Game Winnings & Education Narrative} Identify possible outliers.

The following data values are for 10 popular types of cereal. ​ ​ a.Determine the least squares regression line,if Calories is the y variable. b.Find the predicted value of Calories for Sugar = 9. c.What does the value of the slope of the regression line tell you? ​

Sunshine and Melanoma A medical researcher wanted to examine the relationship between the amount of sunshine (x)in hours,and incidence of melanoma,a type of skin cancer (y).As an experiment he found the number of melanoma cases detected per 100,000 of population and the average daily sunshine in eight counties around the country.These data are shown below. ​ ​ -{Sunshine and Melanoma Narrative} Determine the least squares regression line.

If cov(x,y)= 1260, ,and ,then the coefficient of determination is:

If the regression line is horizontal,then we conclude that y ____________________ (is/is not)related to x.

The symbol for the sample coefficient of correlation is:

If the coefficient of determination is 0.975,then which of the following is true regarding the slope of the regression line?

A regression analysis between sales (in $1000)and advertising (in $100)resulted in the following least squares line: .This implies that if advertising is $800,then the predicted amount of sales (in dollars)is:

Allman Brothers Concert At a recent Allman Brothers concert,a survey was conducted that asked a random sample of 20 people their age and how many concerts they have attended since the first of the year.The following data were collected: An Excel output follows: -{Allman Brothers Concert Narrative} Plot the least squares regression line on the scatter diagram.

Which of the following techniques is used to predict the value of one variable on the basis of other variables?

If the coefficient of correlation is 1.0,then the coefficient of determination must be 1.0.

Game Winnings & Education An ardent fan of television game shows has observed that,in general,the more educated the contestant,the less money he or she wins.To test her belief she gathers data about the last eight winners of her favorite game show.She records their winnings in dollars and the number of years of education.The results are as follows. ​ ​ -{Game Winnings & Education Narrative} Predict with 95% confidence the winnings of a contestant who has 15 years of education.

Given the least squares regression line :

If the regression line is horizontal,the slope is ____________________ and x and y are not related.

The farther a given value of x is from the mean of x,the ____________________ the estimated error becomes.