Mangt 521- Exam 2 Review KSU

SST= SSR+SSE

Relationship between sum of squares

SSR

"Measures how much the " y ̂" values on the estimated regression line deviate""from " y ̄.

VLOOKUP

The _____ function allows the user to pull a subset of data from a larger table of data based on some cri

experimental region

The _____ is the range of values of the independent variables in the data used to estimate the regression model.

Evaluate Formula

The calculations of a cell can be investigated in great detail by using the _____ button.

residual

The difference between the observed value of the dependent variable and the value predicted using the estimated regression equation is known as the _____.

statistical inference

The process of making estimates and drawing conclusions about one or more characteristics of a population through analysis of sample data drawn from the population is known as _____.

shows a periodic pattern lasting more than one year

With reference to time series data patterns, a cyclical pattern is the component of the time series that _____.

Data Table

An Excel _____ quantifies the impact of changing the value of a specific input on an output of interest.

Goal Seek

Excel's _____ tool allows the user to determine the value of an input cell that will cause the value of a related output cell to equal some specified value.

Total Cost = Fixed Cost + Total Variable Cost

Expression for Total cost

scatter charts

For causal modeling, _____ are used to detect linear or nonlinear relationships between the independent and dependent variables

slope of the regression line

In a simple linear regression analysis the quantity that gives the amount by which the dependent variable changes for a unit change in the independent variable is called the _____.

(ABS( Actual-Forecasted)/Actual)*100

Mean Absolute Percentage Error

extrapolation

Prediction of the value of the dependent variable outside the experimental region is called _____.

allow easy instantaneous recalculation for a change in model inputs

Spreadsheet models are referred to as what-if models because they _____

(Actual Demand ^n- Forecasted Demand ^n)/ number of periods

The MAE is

actual value in period t with weight α and the forecast for period t with weight 1 - α

The exponential smoothing forecast for period t + 1 is a weighted average of the _____.

squared differences between actual and predicted y values

The least squares regression line minimizes the sum of the _____

conceptual

The modeling process begins with the framing of a _____ model that shows the relationships between the various parts of the problem being modeled.

Watch Window

The user can monitor how listed cells change with a change in the model without searching through the worksheet or changing from one worksheet to another by using the _____ functionality.

Sum of squares due to error

The value of SSE is a measure of the error in using the estimated regression equation to predict the values of the dependent variable in the sample.

the long-run shift or movement in the time series observable over several periods of time

Trend refers to _____.

0.43

What would be the coefficient of determination if the total sum of squares (SST) is 23.29 and the sum of squares due to regression (SSR) is 10.03? The coefficient of determination r2 = SSR/SST. Substituting the given values, we get r2 = 0.43.

The influence diagram for a portion of the problem is built first and then expanded until the total problem is conceptually modeled

Which of the following approaches is a good way to proceed with the influence diagram building for a problem?

Quadratic regression model

Which of the following regression models is used to model a nonlinear relationship between the independent and dependent variables by including the independent variable and the square of the independent variable in the model?

To uncover a pattern in a time series and then extrapolate the pattern into the future

Which of the following states the objective of time series analysis?

. Validation set

refers to the data set used to compare model forecasts and ultimately pick a model for predicting values of the dependent variable.

Dummy variables

•Dummy variables are often used to model seasonal effects in sales data.

Statistical Inference

•Process of making estimates and drawing conclusions about one or more characteristics of a population (the value of one or more parameters) through the analysis of sample data drawn from the population.

SST

•The corresponding sum of squares is called the total sum of squares (SST).

underestimated

A positive forecast error indicates that the forecasting method _____ the dependent variable.

simple linear regression

A regression analysis involving one independent variable and one dependent variable is referred to as a _____.

Experimental region

•The range of values of the independent variables in the data used to estimate the model. The regression model is valid only over this region

Piecewise linear regression model

•This model will allow us to fit these relationships as two linear regressions that are joined at the value of Months at which the relationship between Months Employed and Sales changes.

Moving averages method

•Uses the average of the most recent k data values in the time series as the forecast for the next period.