Exam 16: Simple Linear Regression and Correlation

In the simple linear regression model, the y-intercept represents the:

In a regression problem, if the coefficient of determination is 0.95, this means that:

Marc Anthony Concert At a recent Marc Anthony 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: -{Marc Anthony Concert Narrative} Identify possible outliers.

Oil Quality and Price Quality of oil is measured in API gravity degrees--the higher the degrees API, the higher the quality.The table shown below is produced by an expert in the field who believes that there is a relationship between quality and price per barrel. A partial Minitab output follows: -{Oil Quality and Price Narrative} Use the residuals to compute the standardized residuals.

Suppose the slope of a simple linear regression line between hours studying and exam score is 5.That means as ____________________ increases by one, ____________________ increases by 5.

The standardized residual is defined as:

The symbol for the sample coefficient of correlation is:

In a simple linear regression problem, the following sum of squares are produced: , , and .The percentage of the variation in y that is explained by the variation in x is:

For a regression analysis to be valid, the error variable must have a(n) ____________________ distribution.

The degrees of freedom for the test statistic for the slope is ____________________.

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

If a single point has a large impact on the equation of the regression line, it is called a(n) ____________________ point.

Cost of Textbooks The editor of a higher education book publisher claims that a large part of the cost of books is the cost of paper.This implies that larger textbooks will cost more money.As an experiment to analyze the claim, a university student visits the bookstore and records the number of pages and the selling price of twelve randomly selected textbooks.These data are listed below. -{Cost of Textbooks Narrative} Draw a scatter diagram of the data.Comment on whether it appears that a linear model might be appropriate.

In a simple linear regression model b₁ is the ____________________ of the straight line.

Comedy Shows Revenues A financier whose specialty is investing in comedy shows has observed that, in general, shows with "big-name" stars seem to generate more revenue than those shows whose stars are less well known.To examine his belief he records the gross revenue and the payment (in $ millions) given to the two highest-paid comedians in the show for ten recently staged shows. -{Comedy Shows Revenues Narrative} Plot the residuals against the predicted values of y.What does the graph tell you?

Sales and Experience The general manager of a chain of department stores believes that experience is the most important factor in determining the level of success of a salesperson.To examine this belief she records last month's sales (in $1,000s) and the years of experience of 10 randomly selected salespeople.These data are listed below. -{Sales and Experience Narrative} Determine the least squares regression line.

Marc Anthony Concert At a recent Marc Anthony 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: -{Marc Anthony Concert Narrative} Does it appear that heteroscedasticity is a problem? Explain.

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} Plot the residuals against the predicted values of y.What does the graph tell you?