States 2- Final

Excel and virtually all other statistical packages report the p-value ____________________________________.

for a two-tailed test that assesses whether the regression coefficient differs from zero

The optimal value of the speed of decline in the exponential smoothing procedure is determined by

trial and error.

A correlation coefficient r = −0.85 could indicate a

very strong negative linear relationship

A regression analysis was conducted using 3 explanatory (X) variables. The null hypothesis for the overall F test is:

H0: β1 = β2 = β3 = 0

Dummy variables take on the values of _________ and are used to model the effects of different levels of qualitative variables.

0 or 1

Conduct a regression analysis in Excel using the following data: X:Y, 12:40, 23:50, 40:59, 33:58, 18:45 What is the value of b1? Include 2 decimal places in your answer.

0.71

In a simple regression analysis based on 30 observations it is found that SSE=2540 and SST=13,870. Calculate R2. Round your answer to 3 decimal places.

0.817

Suppose that we have a qualitative variable Month with categories: January, February, etc. How many dummy variables are needed to describe Month?

11

In a multiple regression, the following sample regression equation was obtained: Y-hat= 152+ 12.9x1 + 2.7x2 What is the value of the intercept?

152

You wish to include marital status in a multiple regression model. The categories you want to include are: Single, Married, Divorced, and Other. How many dummy variables do you need?

3

Conduct a regression analysis in Excel using the following data: X:Y, 12:40, 23:50, 40:59, 33:58, 18:45 What is the value of b0? Include 1 decimal place in your answer.

32.5

The managers of a brokerage firm are interested in finding out if the number of new clients a broker brings into the firm affects the sales generated by the broker. They sample 12 brokers and determine the number of new clients they have enrolled in the last year (X) and their sales amounts in thousands of dollars (Y). The resulting regression equation is: Y-hat = 1.1+17.7x What is the predicted amount of sales (in $1,000s) for a person who brings 25 new clients into the firm? Include 1 decimal place with your answer.

443.6

A candy bar manufacturer is interested in trying to estimate how sales are influenced by the price of their product. To do this, the company randomly chooses 6 small cities and offers the candy bar at different prices. Using candy bar sales as the dependent variable, the company built a simple linear regression on the data. The resulting equation is: Y-hat = 145-48P Where P is the price of the candy bar in dollars. What are the expected sales when the price of the candy bar is $2.00?

49

In a multiple regression, the following sample regression equation was obtained: Y-hat= 152+ 12.9x1 + 2.7x2 What is the predicted value of Y when X1=20 and X2=35? Include 1 decimal place in your answer.

504.5

In a simple regression analysis based on 30 observations it is found that SSE=2540 and SST=13,870. What is the value of se, the standard error of the estimate? Round your answer to 2 decimal places.

9.52

b0, b1, b2

Coefficients for: Intercept, variable 1, variable 2

What is the name of the variable that is used to predict another variable?

Explanatory

A drawback to exponential smoothing is that it gives equal weight to all recent observations equally.

False

Quantitative forecasting procedures are based on the judgement of the forecaster, who uses prior experience and expertise to make forecasts.

False

The moving average method is one of the most complex smoothing techniques used for processing time series.

False

Consider the following simple linear regression model: Y= β0 + β1X + ε When determining whether X significantly influences Y, the null hypothesis takes the form _____________.

H0: β1 = 0

Which of the following variables is not qualitative?

Number of dependents claimed on a tax return

A regression analysis was used for predicting the selling price of a home (in thousands of dollars) using lot size, home size, and whether or not the home has a pool. The presence of a pool was modeled with a dummy variable that has a value of 1 if the home has a pool and a value of 0 if the home does not have a pool. The value of the coefficient of the pool dummy variable is 23.5. What is the interpretation of this coefficient? Pay attention to the units!

On average, a home with a pool will sell for $23,500 more than a home without a pool.

What is the name of the variable that is predicted by another variable?

Response

A trend is an example of what kind of pattern?

Systematic

Seasonality is an example of what kind of pattern?

Systematic

Which of the following is an example of a time series?

The number of daily visitors to the Niagara Falls during the month of April.

A Moving Average is a noncausal model of forecasting.

True

The presence of random error causes what kind of pattern?

Unsystematic

Consider the model Y = β0 + β1X + β2D + ε, where X is a quantitative variable and D is a dummy variable. When D = 1, the predicted value of Y is computed as

Y-hat= (b0+b2) + b1x

A time series is

a set of sequential observations of a variable over time.

When a value of Y is calculated using the regression equation, it is called:

a. y-hat b. the estimated value c. the predicted value Correct- d. All of the Above

A time series with observed long-term upward movements in its values is said to have _________________.

an increasing trend component.

In a simple regression model, the slope (b1) represents

change in estimated Y per unit change in X.

In the simple linear regression model, the slope represents the:

change in y per unit change in x

Generally speaking, if two variables are unrelated (as one increases, the other showsnot pattern), the correlation coefficient will be:

close to zero

In a moving average method, when a new observation becomes available, the new average is computed by including the new observation and ________ .

dropping the oldest observation.

In a simple regression model, the Y-intercept (b0) represents the

predicted value of Y when X = 0

In a simple regression analysis, the Y-intercept (b0) represents the

predicted value of Y when X = 0.

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

predicted value of y when x = 0

Simple linear regression analysis differs from multiple regression analysis in that

simple linear regression uses only one explanatory variable

Simple linear regression analysis differs from multiple regression analysis in that

simple linear regression uses only one explanatory variable while multiple regression uses two or more explanatory variables

For the model Y= β0 + β1X + β2D + ε, which test is used for testing the significance of the dummy variable D?

t-test

The residual is defined as the difference between:

the actual value of y and the estimated value of y.

The slope (b1) represents

the estimated average change in Y per unit change in X

Adjusted R2takes into account

the number of predictor (X) variables and the sample size.