Describe the following functional forms of a regression model clearly explaining under
what circumstances they can be suitably used. Give examples where possible.
c) A lin - log model
d) A log-lin model
c) A lin-log model is a type of regression model in which one of the variables is expressed in logarithmic form. This type of model is useful when the relationship between the two variables is non-linear, and the logarithmic transformation of one of the variables helps to linearize the relationship. For example, a lin-log model could be used to analyze the relationship between a company's sales and its advertising budget, where the sales are expressed in logarithmic form.
d) A log-lin model is a type of regression model in which one of the variables is expressed in linear form. This type of model is useful when the relationship between the two variables is linear, and the linear transformation of one of the variables helps to simplify the analysis. For example, a log-lin model could be used to analyze the relationship between a company's profits and its sales, where the profits are expressed in linear form.