Q$\mathrm{.}6$ Suppose you're working as a data analyst for a retail company, and you're tasked with analyzing sales data to understand product performance across different regions. The dataset includes fields such as product ID$,$ sales quantity, sales amount, and region. Explain the concepts of implicit and explicit measures in Power BI$.$ Provide examples of each type of measure based on the given dataset, distinguishing between measures that are explicitly defined and those that are derived implicitly. How do you create a explicit measure in Tableau? $(4$ marks$)$