Stats midterm
In a linear regression model, the variable (or variables) used for predicting or explaining values of the response variable are known as the _____. It(they) is(are) denoted by x.
independent variables (X)
The coefficient of determination _____.
is used to evaluate the goodness of fit
Variable being predicted Y
Dependent variable or response:
Consists of techniques that use models constructed from past data to predict the future or ascertain the impact of one variable on another.
Predictive analytics - Linear regression. - Time series analysis.
Indicates a best course of action to take: • Provide a forecast or prediction, but do not provide a decision. • A forecast or prediction, when combined with a rule, becomes a prescriptive model.
Prescriptive Analytics:
Which of the following analytical techniques helps us arrive at the best decision?
Prescriptive analytics
involves the use of probability and statistics to construct a computer model to study the impact of uncertainty on a decision.
Simulation
the positive square root of the variance.
Standard deviation
A regression analysis involving two or more independent variables.
Multiple linear regression:
A line that provides an approximation of the relationship between the variables.
Trendline
A _____ is used to visualize sample data graphically and to draw preliminary conclusions about the possible relationship between the variables.
scatter chart
A regression analysis involving one independent variable and one dependent variable is referred to as a _____.
simple linear regression
For data having a bell-shaped distribution, approximately _____ percent of the data values will be within one standard deviation of the mean.
68
Scientific process of transforming data into insight for making better decisions.
Business analytics
A useful type of table for describing data of two variables. PivotTable
Crosstabulation
set of techniques that describes what has happened in the past; ex: Data queries. • Reports. • Descriptive statistics. • Data visualization • Data-mining •what-if
Descriptive analytics
A variable used to model the effect of categorical independent variables in a regression model is known as a _____.
Dummy variable
Variables being used to predict the value of the dependent variable. X
Independent variables or predictor variables:
_____refers to the technology that allows data, collected from sensors in all types of machines, to be sent over the Internet to repositories where it can be stored and analyzed.
Internet of Things (IoT)
the technology that allows data, collected from sensors in all types of machines, to be sent over the Internet to repositories where it can be stored and analyzed.
Internet of Things (IoT)
Predictive and prescriptive analytics are sometimes referred to as
advanced analytics
A normally distributed error term with a mean of zero would _____.
allow more accurate modeling
A _____ determines how far a particular value is from the mean relative to the data set's standard deviation
z-score
measures the relative location of a value in the data set
z-score
When the mean value of the dependent variable is independent of variation in the independent variable, the slope of the regression line is
zero
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?
Quadratic regression model
A regression analysis for which any one unit change in the independent variable, x, is assumed to result in the same change in the dependent variable, y.
Simple linear regression:
a measure of variability that utilizes all the data.• It is based on the deviation about the mean, which is the difference between the value of each observation (xi) and the mean.
Variance
In the simple linear regression model, the _____ accounts for the variability in the dependent variable that cannot be explained by the linear relationship between the variables.
error term
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 _____.
slope of the regression line
The least squares regression line minimizes the sum of the _____.
squared differences between actual and predicted y values
Prediction of the value of the dependent variable outside the experimental region is called
extrapolation
The graph of the simple linear regression equation is a
straight-line
The _____ is a measure of the error that results from using the estimated regression equation to predict the values of the dependent variable in the sample.
sum of squares due to error (SSE)
The use of analytical techniques for better understanding patterns and relationships that exist in large data sets Ex: • Cluster analysis. • Sentiment analysis.
Data mining:
A _____ is a graphical presentation of the relationship between two quantitative variables.
a scatter chart
Which one of the following is used in predictive analytics? a. Linear regression b. Data dashboard c. Data visualization d. Optimization model
a. Linear regression
The _____ is a measure of the goodness of fit of the estimated regression equation. It can be interpreted as the proportion of the variability in the dependent variable y that is explained by the estimated regression equation.
coefficient of determination
a descriptive statistic that indicates how large the standard deviation is relative to the mean. (Cov/mean)
coefficient of variation
In a linear regression model, the variable that is being predicted or explained is known as _____. It is denoted by y and is often referred to as the response variable.
dependent variable
The variance is based on the
deviation about the mean
Advanced analytics generally refers to
predictive and prescriptive analytics
The simplest measure of variability is the _____.
range
A _____ is a line that provides an approximation of the relationship between the variables.
treadle