Question

What is the common difference and ninth term for the following sequence: 3,5/2,2,3/2,1

Answer 1

Answer:

Common Difference: $-\frac{1}{2}$

The ninth term: -1

Step-by-step explanation:

The sequence can be written like this,

3, 2.5, 2, 1.5, 1, ....

Here the common difference is clearly -0.5 or $-\frac{1}{2}$, and we can conclude that $n^{th}$ number is $3 - 0.5(n-1)$. So the 9th term is,

$3 - 0.5(9 - 1)\\= -1$