Need help on the last three (The ones with x's) (D) and (E)

For part d:

The objective is to predict the life expectancy of a child born in 2019.

According to the part a the equation for linear regression line is given by the formula:

E(t)=.15t+77.74; where year 2005 is taken as the initial year, i.e. t=0 when year is 2005.

Now to predict the life expectancy of a child born in 2019 first find the t since 2005, as

t=2019-2005=14

Now the life expectancy of a child born in 2019 can be calculated by finding E(t) when t=14, as

$\begin{array}{c}E\left(14\right)=.15\left(14\right)+77.74\\ =2.1+77.74=79.84\end{array}$

Thus, life expectancy of a child born in 2019 is approx. 79.8 years. 

For part e:

The objective is to predict the life expectancy of a child born in 1580.