Virtual Labs

3A regression Is the slope of a line zero

If Y = a+b_YXX and X = a'+b_XYY be the two regression lines then the correlation between X and Y(r) can be given as :

a: r = b_XY · b_YX Explanation

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b: r = b_XY + b_YX Explanation

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c: r = √(b_XY · b_YX) Explanation

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d: r = b_XY - b_YX Explanation

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For the two regression lines of Y on X and X on Y respectively, if the regression coefficient b_YX and b_XY both are positive then:

a: the correlation coefficient is negative Explanation

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b: correlation coefficieint is zero Explanation

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c: correlation coefficient is positive Explanation

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d: correlation coefficient equals to ratio of regression coefficients Explanation

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If b_XY > 1 then b_YX should be :

a: less than 1 Explanation

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b: equal to 1 Explanation

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c: 1+b_XY Explanation

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d: 1-b_XY Explanation

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In the least square regression, which of the following is not an assumption about the error term?

a: the expected value of error term is 1 Explanation

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b: the variance of error terms is same for all values of x Explanation

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c: the error terms are independent Explanation

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d: the error term is normally distributed Explanation

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If r is the correlation coefficient between X and Y then r² is

a: coefficient of variation Explanation

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b: coefficient of standard deviation Explanation

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c: coefficient of association Explanation

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d: coefficient of determination Explanation

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In a regression analysis if r²=1 then,

a: SSE must be equal to 1 Explanation

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b: SSE must be equal to zero Explanation

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c: SSE must be negative Explanation

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d: SSE can be any positive value Explanation

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A residual plot displays :

a: displays residuals of the dependent variable versus residuals of independent variable Explanation

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b: residuals of independent variable versus the dependent variable Explanation

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c: independent variable versus residual of the dependent variable Explanation

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d: independent variable versus dependent Explanation

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When the error terms have constant variance then the residual plot shows the pattern :

a: that fans out Explanation

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b: that funnels in Explanation

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c: fans out but funnels in Explanation

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d: that forms a horizontal band pattern Explanation

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