Answer:
The sequence is an arithmetic sequence.
Common difference = 0.6
Explanation:
Given
-2.8, -2.2, -1.6, -1.0
Required
State if it's an arithmetic progression
Also state its common difference
To know if a sequence is arithmetic or not, we simply check for common difference
Common difference is calculated by subtracting a lower term with its immediate higher time;
In other words

Where T represent Term and the number represent their positions;
So, from the given above

Calculating


Calculating


Calculating


Notice that all the above workings gave the same result;
This shows that the sequence is an arithmetic sequence.
The result of each workings above is the common difference
Common difference = 0.6