I recommend cultivating a “can-do” attitude with Math in preparation for the GEP test if you are pursuing such, and such an attitude does not come in a month, or even a year. My mum made me practice Math since young, such that in school, most of the time, I can solve the questions. And it’s that feeling of “I can do it” that also makes me enjoy logical puzzles and the like. In fact, that “I can do it” attitude carries on into all other areas of my life. Rarely do I think something is beyond my ability — I hold an attitude that with sufficient focus and time, I can do anything.
These expressions are equal! So what does this mean? Let’s first define P(data; μ, σ)? It means “the probability of observing the data with model parameters μ and σ”. It’s worth noting that we can generalise this to any number of parameters and any distribution.