If I by 20 pens and get them for 55 how much money am I making

What situation is an example of an observational study

Im gonna fail 7th grade selective breeding 1. creates offspring which are genetically identical to the parent 2. is the process of breeding only organisms with desirable traits 3. involves the removal of the nucleus of a cell 4. combines traits from organisms of different species

What is the slope of the line (-7,2) (4,6)