Here’s a brief rewording/summary of each of the two challenges.
Question 4
 Make a function named
double_index
.
 The function should take in 2 parameters:
lst
(which is a list) and index
(which is an integer).
 The function should return a new list.
 This new list should be the same as
lst
(the list that was passed into the function) except for one thing.
 The one difference should be that the element at the
index
index of the list should be doubled. For example, let’s say double_index([2, 4, 6, 8], 1)
was called. [2, 8, 6, 8]
should be returned.
[2, 4, 6, 8] < list
   
v v v v
0 1 2 3 < indices
Since 4
is the element at index 1
, we should double it, making it 8
. The new list with the doubled value should be returned.
Question 5
 Make a function named
middle_element
.
 The function should take in one parameter:
lst
(a list).
 The function should return one of two things based on the number of elements in
lst
.
 If there are an odd number of elements in
lst
, the function should return the element in the middle of the list.
 If there are an even number of elements in
lst
, the function should return the average of the middle two elements in the list.
Odd number of elements example:
[2, 4, 6] < there are an odd number of elements (3)

v
middle
The function should return 4 since it is the middle element.
Even number of elements example:
[2, 4, 6, 8] < there are an even number of elements (4)
 
v v
middle 2
The function should return 5 since it is the average of the
middle 2 elements (which are 4 and 6).