2. Show that R-squared (for a simple linear regression) is equal to the square of the...
#1 In simple linear regression, r is the: a) coefficient of determination. b) mean square error. c) correlation coefficient. d) squared residual. #2 In regression analysis, with the model in the form y = β0 + β1x + ε, x is the a) estimated regression equation. b) y-intercept. c) slope. d) independent variable. #3 A regression analysis between sales (y in $1,000s) and advertising (x in dollars) resulted in the following equation. ŷ = 40,000 + 3x The above equation...
Consider the following example of a simple linear regression in R. x = c(-1,0,1) y = c(0,4,2) lm(y"x) ## Call: ## lm(formula = y ~ x) ## Coefficients: # (Intercept) 2 Please write down the design matrix X and compute the values of the slope in the R output (make sure you show the details). Please interpret both intercept and slope in the simple linear regression
2. Consider the simple linear regression model: where e1, .. . , es, are i.i.d. N (0, o2), for i= 1,2,... , n. Suppose that we would like to estimate the mean response at x = x*, that is we want to estimate lyx=* = Bo + B1 x*. The least squares estimator for /uyx* is = bo bi x*, where bo, b1 are the least squares estimators for Bo, Bi. ayx= (a) Show that the least squares estimator for...
A simple linear regression of Y on X reveals that the slope b is 3; the standard deviation of X is 2; and the standard deviation of Y is 8. What is the correlation coefficient between X and Y? Show steps.
1. If a true model of simple linear regression reads: yi −y ̄ = β0 +β1(xi −x ̄)+εi for i = 1, 2, · · · , n, showβ0 =0andβˆ0 =0. (1pt) (hint: use the formula of estimator βˆ0 = y ̄ − βˆ1x ̄.)
(13 points) Suppose you have a simple linear regression model such that Y; = Bo + B18: +€4 with and N(0,0%) Call: 1m (formula - y - x) Formula: F=MSR/MSE, R2 = SSR/SSTO ANOVA decomposition: SSTOSSE + SSR Residuals: Min 1Q Modian -2.16313 -0.64507 -0.06586 Max 30 0.62479 3.00517 Coefficients: Estimate Std. Error t value Pr(> It) (Intercept) 8.00967 0.36529 21.93 -0.62009 0.04245 -14.61 <2e-16 ... <2e-16 .. Signif. codes: ****' 0.001 '** 0.01 '* 0.05 0.1'' 1 Residual standard...
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Following is a simple linear regression model: y = a + A + & The following results were obtained from some statistical software. R2 = 0.523 Syx (regression standard error) = 3.028 n (total observations) = 41 Significance level = 0.05 = 5% Variable Interecpt Slope of X Parameter Estimate 0.519 -0.707 Std. Err. of Parameter Est 0.132 0.239 Note: For all the calculated numbers, keep three decimals. Write the fitted model (5 points) 2. Make a prediction...
al Random Variables Mark and Recapture Linear Regression Linear Regression Exercise. Show that the maximum likelihood estimator for σ2 is where yi + ßxi. are the predicted values from the regression line. Frequently, software will report the unbiased estimator. For ordinary least square procedures, this is k-1 For the measurements on the lengths in centimeters of the femur and humerus for the five specimens of Archeopteryx, we have the following R output for linear regression. 10 Mark and Recapture Linear...
1. Consider the simple linear regression model: Ү, — Во + B а; + Ei, where 1, . . , En are i.i.d. N(0,02), for i1,2,... ,n. Let b1 = s^y/8r and bo = Y - b1 t be the least squared estimators of B1 and Bo, respectively. We showed in class, that N(B; 02/) Y~N(BoB1 T;o2/n) and bi ~ are uncorrelated, i.e. o{Y;b} We also showed in class that bi and Y 0. = (a) Show that bo is...
Q5). Show that in a simple linear regression Σεί 0 (a). (). (X,Y) is a point on the fitted regression line. (d). Verify parts (a), (b), and (c) for the data in the folder "Regression and Correlation" at the course blackboard site. You are free to use software or calculator for the verification.
Q5). Show that in a simple linear regression Σεί 0 (a). (). (X,Y) is a point on the fitted regression line. (d). Verify parts (a), (b), and...