Linear Regression

IMPORTANT

Linear Regression: Overview

This Topic covers sub-topics such as Correlation, Correlation Coefficient, Scatter Diagrams, Method of Least Squares, Co-variance, Types of Correlation, Simple Linear Regression, Correlation Analysis, Positive Correlation and, Negative Correlation

Important Questions on Linear Regression

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Find the value of y at x=4, given some set of values (2,4),(6,7).

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Consider the value of r and line of best fit together with their definitions to your answer.  All the original x -values are increased by adding 5 and all the original y-values are decreased by subtracting 4 if a set of bivariate data has a Pearson product moment correlation coefficient of r=0.87 for 25 pairs (x, y). The y on x line of best fit is given by y=15x+11.

State the new value of r

State the new value for the gradient of the y on x line of best fit.

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When the gradient of the regression line is positive, the correlation is strong. State whether the given statement is true or false.

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Explain perfect positive correlation with a scatter plot.

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Explain the importance and significance of correlation.

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State the types of correlation.

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The following graph has

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The following graph has

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Determine the value of correlation coefficient for the scatter diagram given below.

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Identify the type of correlation between the weight and income of individuals.

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Bivariate statistics compare three variables.

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Define bivariate statistics.

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Find the equation of least-squares regression line from the given data.

x=10,y=50,xy=100,x2=50 and n=4

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Find the equation of least-squares regression line from the given data.

x=28,y=61.8,xy=314.8,x2=140 and n=7

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If n=4, x = 20, y = 40, xy = 214,y2 = 340x2 = 220, then find the regression equation of X on Y.

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Identify if the following data is Univariate data or Bivariate data

Traffic accidents along with the weather on a particular day

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Interpret the scatter diagram given below and describe whether the diagram shows strong/weak/no correlation. If the variables are correlated, describe the correlation using the words positive/negative; linear/non-linear.

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Interpret the scatter diagram given below and describe whether the diagram shows strong/weak/no correlation. If the variables are correlated, describe the correlation using the words positive/negative; linear/non-linear.

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Identify if the following data is Univariate data or Bivariate data

Ice cream sales compared to the temperature that day

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Segmented linear regression is segmented regression whereby the relations in the intervals are obtained by _____.