What are some Applications Using Linear Models?
The major practical application for linear models is to model linear trends and rates in the real world.
For example, if you wanted to wanted to see how much money you were spending over time, you could find how much money you had spent at a given time for several points in time, and then make a model to see what rate you were spending at.
Also, in cricket matches, they use linear models to model the run rate of a given team. They do this by taking the number of runs a team has scored in a certain number of overs, and divide the two to come up with a runs per over rate.
However, keep in mind that these real-life linear models are usually always averages, or approximations . This is just due to life being so random, but we never actually stick to those rates we have. For example, if a cricket team's run rate was judged to be 10.23 runs per over, it doesn't mean that they scored exactly 10.23 runs every over, but rather that they scored that many on average.
Hope that helped :)