What different models have been used to calculate this and why have there been so many different forecasts? Which models are the most reliable ones and why?

Modelling the spread and the death rate of the coronavirus

Modelling the spread and the death rate of the coronavirus: What different models have been used to calculate this and why have there been so many different forecasts? Which models are the most reliable ones and why?

The introduction (that should be around 300-400 words) need to fulfill the below criteria to 100%,e read carefully:

Say exactly what the paper examines (the research question as above) and what type of math that will be used. Specify clearly which mathematical rules that will be used

A clear hypothesis

A motivation for doing this, why it is important to understand

Which data that will be used

What mathematical software that will be used, if any (e.g. Desmos or Autograph)