question is :
Statistical inference is a concept that is not too difficult to understand when using cross-sectional data. For example, a population mean is not the same as a sample mean. There is uncertainty regarding the population mean given sample information and thus we have to rely on confidence intervals. But what about time-series? How can you make statistical inference about some population, given a sample at hand (using quarterly data from 1960-2020, for example) Describe the relationship between a sample and a population when using time series data. Your answer should not exceed the word limit of 300 words.