Problem $11$: Smoothing Data

When data is temporal $($ordered by time$),$ we sometimes want to $$smooth$"$ it by giving a simple

average. The simplest is taking two consecutive values and finding their average. Given a

$($possibly empty$)$ list of numbers lst $=[$x$0,$x$1,...,$xn$]$ the function smooth$($lst$)$ returns:

$$ The string $$AveError: list empty" if the list is empty

$$ lst if list only contains one number

$$ a new list of numbers $[$y$0,$y$1,...,$yn$1]$ such that yi $=$

xi$+$xi$+1$

$2$

The following code

$1$ data $=[[],[1],[1,2],[1,2,2,3],[0,2,4,6,8]]$

$2$ for d in data :

$3$ print $($ smooth $($ d $))$

produces

$1$ AveError : list empty

$2[1]$

$3[1\mathrm{.}5]$

$4[1\mathrm{.}5,2\mathrm{.}0,2\mathrm{.}5]$

$5[1\mathrm{.}0,3\mathrm{.}0,5\mathrm{.}0,7\mathrm{.}0]$

Deliverables for Problem $11$

$$ Complete the function.

$$ Round to two decimal places.