Data on U.S. infant mortality rates per 1000 live births was collected for years 1960-1979. The variables studied were myx = year and y = infant mortality rate. Output from a simple linear regression analysis appears below.

a. Write down the equation of the least squares regression line.

b. Is there evidence that infant mortality is changing over the years? Test the appropriate hypothesis at the 0.05 significance level.

c. According to the regression model, how much is infant mortality expected to change from 1965 to 1975?

d. According to the model, what is the expected infant mortality rate in 2020? Why might this estimate be unreliable?

Coefficients : Estimate Std. Error t value Pr(>Itl) (Intercept) 1471.96468 61 . 78189 23.82 3.85e-10 *** myx -0. 73716 0. 03132 -23.54 4.35e-10 *** - - - Signif. codes : 0 '* * *' 0.001 ' **' 0.01 '*' 0.05 '. ' 0.1 ' ' 1 Residual standard error: 0.5733 on 10 degrees of freedom Multiple R-squared: 0.9823, Adjusted R-squared: 0.9805 F-statistic: 553.9 on 1 and 10 DF, p-value: 4.348e-10