Vector selection: the good times $(4)$

Another way to tackle the previous exercise is by using the names of the vector elements $($Monday$,$ Tuesday, $...)$ instead of their numeric positions. For example,

poker$\_$vector$["$Monday$"]$

will select the first element of poker$\_$vector since "Monday" is the name of that first element.

Just like you did in the previous exercise with numerics, you can also use the element names to select multiple elements, for example:

poker$\_$vector$[$c$("$Monday$",$ "Tuesday"$)]$

$()$ Instructions

Select the first three elements in poker$\_$vector by using their names:

"Monday" $,$ "Tuesday" and "Wednesday" $.$ Assign the result of the selection to poker$\_$start $.$

Calculate the average of the values in poker$\_$start with the mean$()$ function. Simply print out the result so you can inspect it$.$