To find the arithmetic mean of two numbers, add them and divide by 2.
2.5
Practice makes perfect
We want to find the missing term of the given arithmetic sequence.
..., -3, a_n, 8, ...Note that the missing term is the arithmetic mean of the previous and the following terms, which are given in the exercise.
To find the arithmetic mean of two numbers, we add them and divide by 2.
a_n=a_(n-1)+a_(n+1)/2
Let's substitute -3 for a_(n-1) and 8 for a_(n+1) in the above equation.
