Important Online MCQs Multivariate 2

The post is about the MCQs Multivariate Analysis test. It includes a Variance-Covariance matrix, Principal Component Analysis, Factor Analysis, Factor Loading, etc. Let us start with the Online MCQs Multivariate Quiz.

Online Multivariate Quiz

1. Factor analysis pinpoints the clusters of correlations between variables and for each cluster

 
 
 
 

2. In the relation $\Sigma = V^{1/2} \rho ^{1/2} V^{1/2}$, the $V^{1/2} is called

 
 
 
 

3. In multivariate analysis the distribution of $\overline{X}$ is

 
 
 
 

4. An advantage of using an experimental multivariate design over separate univariate designs is that using the multivariate analysis – – – – – – -.

 
 
 
 

5. In principal component analysis (PCA) the first component contains

 
 
 
 

6. In principal component analysis, the components are

 
 
 
 

7. A multivariate statistic that allows you to analyze several dependent variables from an experimental design simultaneously is

 
 
 
 

8. In factor analysis the reliable variance

 
 
 
 

9. Ffactor loading is

 
 
 
 

10. In multivariate analysis Var-Cov matrix is

 
 
 
 

11. If $X \sim N (\mu, \Sigma)$ then $(X-\mu)’ \Sigma^{-1} (X-\mu)$ is distributed as

 
 
 
 

12. A multivariate statistic that allows you to investigate the relationship between two sets of variables is

 
 
 
 

13. In PCA, when the variables are measured in different units then PC extracted on the basis of

 
 
 
 

14. ——- is used for causal analysis

 
 
 
 

15. In multivariate analysis, $n(\overline{x} – \mu)’ S^{-1} (\overline{x} – \mu)$ is called

 
 
 
 

16. In multivariate analysis the distribution of the sample covariance matrix is

 
 
 
 

17. The goal of multiple regression is to

 
 
 
 

18. A factor is a combination of variables

 
 
 
 

19. Correlational multivariate analysis includes

 
 
 
 

20. A factor loading of 0.80 means, generally speaking, that

 
 
 
 

An application of different statistical methods applied to the economic data used to find empirical relationships between economic data is called Econometrics. In other words, Econometrics is “the quantitative analysis of actual economic phenomena based on the concurrent development of theory and observation, related by appropriate methods of inference”.

Online MCQs Multivariate

  • In multivariate analysis Var-Cov matrix is
  • In the relation $\Sigma = V^{1/2} \rho ^{1/2} V^{1/2}$, the $V^{1/2} is called
  • If $X \sim N (\mu, \Sigma)$ then $(X-\mu)’ \Sigma^{-1} (X-\mu)$ is distributed as
  • In multivariate analysis, $n(\overline{x} – \mu)’ S^{-1} (\overline{x} – \mu)$ is called
  • In multivariate analysis the distribution of $\overline{X}$ is
  • In multivariate analysis the distribution of the sample covariance matrix is
  • In factor analysis the reliable variance
  • In principal component analysis (PCA) the first component contains
  • In principal component analysis, the components are
  • In PCA, when the variables are measured in different units then PCs extracted on the basis of
  • The goal of multiple regression is to
  • A multivariate statistic that allows you to investigate the relationship between two sets of variables is
  • Correlational multivariate analysis includes
  • An advantage of using an experimental multivariate design over separate univariate designs is that using the multivariate analysis – – – – – – -.
  • A multivariate statistic that allows you to analyze several dependent variables from an experimental design simultaneously is
  • ——- is used for causal analysis
  • Factor loading is
  • A factor loading of 0.80 means, generally speaking, that
  • A factor is a combination of variables
  • Factor analysis pinpoints the clusters of correlations between variables and for each cluster
MCQs Multivariate itfeature.com
  • Partial Least Squares (PLS) Regression is an example of multivariate analysis (MVA).
  • Multivariate Multiple Regression is a method of modeling multiple dependent variables, with a single set of predictor variables.
  • Testing text and visual elements on a webpage together.
  • An example of multivariate data is Vital signs recorded for a newborn baby: This includes multiple variables such as heart rate, respiratory rate, blood pressure, and temperature.

Online MCQs Multivariate

Online MCQs about various Subjects

Important Online Multivariate MCQ

Multivariate Analysis term includes all statistics for more than two simultaneously analyzed variables. The post contains a Multivariate Quiz.

Online Multivariate MCQs

MCQs Cluster Analysis 6Multivariate Quiz 5Multivariate MCQs 4
Multivariate MCQs 3Multivariate MCQs 2Multivariate MCQs 1

Multivariate analysis is based upon an underlying probability model known as the Multivariate Normal Distribution (MND). The objective of scientific investigations to which multivariate methods most naturally lend themselves includes. Multivariate analysis is a powerful technique for analyzing data that goes beyond the limitations of simpler, single-variable methods.

Online Multivariate MCQ
  • Data reduction or structural simplification
    The phenomenon being studied is represented as simply as possible without sacrificing valuable information. It is hoped that this will make interpretation easier.
  • Sorting and Grouping
    Graphs of similar objects or variables are created, based on measured characteristics. Alternatively, rules for classifying objects into well-defined groups may be required.
  • Investigation of the dependence among variables
    The nature of the relationships among variables is of interest. Are all the variables mutually independent or are one or more variables depend on the observation of the other variables?
  • Prediction
    Relationships between variables must be determined for predicting the values of one or more variables based on observation of the other variables.
  • Hypothesis Construction and testing
    Specific statistical hypotheses, formulated in terms of the parameter of the multivariate population, are tested. This may be done to validate assumptions or to reinforce prior convictions.
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Multivariate analysis provides a comprehensive and robust way to analyze the data. It leads to better decision-making across various fields. Multivariate analysis is a vital tool for researchers and data scientists seeking to extract deeper insights from complex datasets.

Online MCQs Test With Answers Website

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Easy Multivariate Analysis MCQs – 1

Multivariate Analysis term includes all statistics for more than two simultaneously analyzed variables. The post contains Multivariate Analysis MCQs. Let us start with the Online Multivariate Analysis MCQs test.

Please go to Easy Multivariate Analysis MCQs – 1 to view the test

Multivariate Analysis MCQs

Multivariate Analysis MCQs

  • If $A$ and $B$ are two $n \times n$ matrices, which of the following is not always true?
  • Let $x_1, x_2, \cdots, x_n$ be a random sample from a joint distribution with mean vector $\mu$ and covariance $\sigma$. Then $\overline{x}$ is an unbiased estimator of $\mu$ and its covariance matrix is:
  • Let $x$ be distributed as $N_p(\mu, \sigma)$ with $|\sigma | > 0$, then $(x-\mu)’ \sigma^{-1} (x-\mu)$ is distributed as:
  • Let $A$ be a $k\times k$ symmetric matrix and $X$ be a $k\times 1$ vector. Then
  • Let $x_1, x_2, \cdots, x_n$ be a random sample of size $n$ from a p-variate normal distribution with mean $\mu$ and covariance matrix $\sigma$, then
  • The set of all linear combination of $X_1, X_2, \cdots, X_k$ is called
  • A set of vectors $X_1, X_2, \cdots, X_n$ are linearly independent if
  • Length of vector $\underline{X}$ is calculated as
  • A matrix in which the number of rows and columns are equal is called
  • A matrix $A_{m\times n}$ is defined to be orthogonal if
  • If $A$ is a square matrix of order ($m \times m$) then the sum of diagonal elements is called
  • The rank of a matrix $\begin{bmatrix}1 & 0 & 1 & 0 & 2 \ 0 & 0 & 1 & 1 & 2 \ 1 & 1 & 0 & 0 & 2 \ 0 & 1 & 1 & 1 & 3\end{bmatrix}$ is
  • If $A$ is a square matrix, then $det(A – \lambda)=0$ is known as
  • The pdf of multivariate normal distribution exists only when $\sigma$ is
  • The eigenvalue is the factor by which the Eigenvector is
  • Eigenvalue is often introduced in the context of
  • How many Eigenvalues does a 2 by 2 matrix have?
  • What are Eigenvalues?
  • Eigenvalues and Eigenvectors are only for the matrices
  • A square matrix $A$ and its transpose have the Eigenvalues

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EigenValues and EigenVectors (2020)

Introduction to Eigen Values and Eigen Vectors

Eigenvalues and eigenvectors of matrices are needed for some of the methods such as Principal Component Analysis (PCA), Principal Component Regression (PCR), and assessment of the input of collinearity.

Eigenvalues and Eigenvectors

For a real, symmetric matrix $A_{ntimes n}$ there exists a set of $n$ scalars $lambda_i$, and $n$ non-zero vectors $Z_i,,(i=1,2,cdots,n)$ such that

begin{align*}
AZ_i &=lambda_i,Z_i\
AZ_i – lambda_i, Z_i &=0\
Rightarrow (A-lambda_i ,I)Z_i &=0
end{align*}

The $lambda_i$ are the $n$ eigenvalues (characteristic roots or latent root) of the matrix $A$ and the $Z_i$ are the corresponding (column) eigenvectors (characteristic vectors or latent vectors).

There are non-zero solutions to $(A-lambda_i,I)=0$ only if the matrix ($A-lambda_i,I$) is less than full rank (only if the determinant of $(A-lambda_i,I)$ is zero). $lambda_i$ are obtained by solving the general determinantal equation $|A-lambda,I|=0$.

The determinant of $(A-lambda,I)$ is an $n$th degree polynomial in $lambda$. Solving this equation gives the $n$ values of $lambda$, which are not necessarily distinct. Each value of $lambda$ is used in equation $(A-lambda_i,I)Z_i=0$ to find the companion eigenvectors $Z_i$.

When the eigenvalues are distinct, the vector solution to $(A-lambda_i,I)Z_i=0$ is unique except for an arbitrary scale factor and sign. By convention, each eigenvector is defined to be the solution vector scaled to have unit length; that is, $Z_i’Z_i=1$. Furthermore, the eigenvectors are mutually orthogonal; ($Z_i’Z_i=0$ when $ine j$).

When the eigenvalues are not distinct, there is an additional degree of arbitrariness in defining the subsets of vectors corresponding to each subset of non-distinct eigenvalues.

Eigen Values and Eigen Vectors Examples

Example: Let the matrix $A=begin{bmatrix}10&3\3 & 8end{bmatrix}$.

The eigenvalues of $A$ can be found by $|A-lambda,I|=0$. Therefore,

begin{align*}
|A-lambda, I|&=Big|begin{matrix}10-lambda & 3\ 3& 8-lambdaend{matrix}Big|\
Rightarrow (10-lambda)(8-lambda)-9 &= lambda^2 -18lambda+71 =0
end{align*}

By Quadratic formula, $lambda_1 = 12.16228$ and $lambda_2=5.83772$, arbitrarily ordered from largest to smallest. Thus the matrix of eigenvalues of $A$ is

$$L=begin{bmatrix}12.16228 & 0 \ 0 & 5.83772end{bmatrix}$$

The eigenvectors corresponding to $lambda_1=12.16228$ are obtained by solving

$(A-lambda_2,I)Z_i=0$ for the element of $Z_i$;

begin{align*}
(A-12.16228I)begin{bmatrix}Z_{11}\Z_{21}end{bmatrix} &=0\
left(begin{bmatrix}10&3\3&8end{bmatrix}-begin{bmatrix}12.162281&0\0&12.162281end{bmatrix}right)begin{bmatrix}Z_{11}\Z_{21}end{bmatrix}&=0\
begin{bmatrix}-2.162276 & 3\ 3 & -4.162276end{bmatrix}begin{bmatrix}Z_{11}\Z_{21}end{bmatrix}&=0
end{align*}

Arbitrary setting $Z_{11}=1$ and solving for $Z_{11}$, using first equation gives $Z_{21}=0.720759$. Thus the vector $Z_1’=begin{bmatrix}1 & 0.72759end{bmatrix}$ statisfy first equation.

$Length(Z_1)=sqrt{Z_1’Z_1}=sqrt{1.5194935}=1.232677$, where $Z’=0.999997$.

begin{align*}
Z_1 &=begin{bmatrix} 0.81124&0.58471end{bmatrix}\
Z_2 &=begin{bmatrix}-0.58471&0.81124end{bmatrix}
end{align*}

The elements of $Z_2$ are found in the same manner. Thus the matrix of eigenvectors for $A$ is

$$Z=begin{bmatrix}0.81124 &-0.58471\0.8471&0.81124end{bmatrix}$$

Note that matrix $A$ is of rank two because both eigenvalues are non-zero. The decomposition of $A$ into two orthogonal matrices each of rank one.

begin{align*}
A &=A_1+A_2\
A_1 &=lambda_1Z_1Z_1′ = 12.16228 begin{bmatrix}0.81124\0.58471end{bmatrix}begin{bmatrix}0.81124 & 0.58471end{bmatrix}\
&= begin{bmatrix}8.0042 & 5.7691\ 5.7691&4.1581end{bmatrix}\
A_2 &= lambda_2Z_2Z_2′ = begin{bmatrix}1.9958 & -2.7691\-2.7691&3.8419end{bmatrix}
end{align*}

EigenValues and EigenVectors (2020)

Thus the sum of eigenvalues $lambda_1+lambda_2=18$ is $trace(A)$. Thus the sum of the eigenvalues for any square symmetric matrix is equal to the trace of the matrix. The trace of each of the component rank $-1$ matrix is equal to its eigenvalue. $trace(A_1)=lambda_1$ and $trace(A_2)=lambda_2$.

In summary, understanding eigenvalues and eigenvectors is essential for various mathematical and scientific applications. They provide valuable tools for analyzing linear transformations, solving systems of equations, and understanding complex systems in various fields.

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