Definition: In this task you are given a list of numbers and you need to find the average of each two consecutive values. The average of two numbers a and b is calculated as: (a + b) /2. The output should be a list of the averages of each two consecutive values. A list is presented with two brackets and comma-separated values, like: [1,2,3].
Input: [83, -90, -68, -70, 49, 30, 17, -85, 88, 91, -92, 59, 89, -100, -83]
Output:

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
user
[-3.5, -79.0, -69.0, -10.5, 39.5, 23.5, -34.0, 1.5, 89.5, -0.5, -16.5, 74.0, -5.5, -91.5]