ou run the following regression on 189 observations collectedusing a random sample to examine which factors...

ou run the following regression on 189 observations collectedusing a random sample to examine which factors affect the weight of babiesat birth:y=β0+β1x1+β2x2+β3x3+εwhere•yis the birth weight in grams•x1is number of times the mother visited the physician during the 1sttrimester•x2is mother’s weight at last menstrual period in kilograms•x3is the age of the mother in yearsYou obtain the following results

Variable	Estimate, bi	Standard Error Sbi
x1	15.66	51.103
x2	4.124	1.757
x3	7.356	10.282
bo	2225.513	301.536

(a) Interpret the estimateb1= 15.660

.(b) Calculate and interpret a 95% confidence interval forβ3.In addition, you also obtain the following results from the estimation of the model:

SSR= 3822396

SSE= 96092902

(c) Calculate and interpret the value of the coefficient of determination.

(d) Test the validity of the model at a significance level of 5%. What isthe null hypothesis and the alternative? What is the test statistic?What is your conclusion?

(e) You obtain the two following graphs from the estimation results: A histogram of the residuals ˆε, and a scatter plot of the residuals ˆεandthe predicted values ˆy.

(Assume)

What do these two graphs tell you about the necessary conditions that must hold in order for the regression analysis to be valid?

Expert Solution

orchestra answered 2 years ago

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