An electric device delivers a current of [tex]$15.0 A$[/tex] for 30 seconds. How many electrons flow through it?
Answer (2)
In the context of data warehousing and business intelligence, facts are measurements or metrics for which data is collected. The question concerns the additivity of the 'Gross_Profit_Margin' column.
The additivity of measures relates to how you can aggregate fact data across the dimensions of a database. Here's what the options mean:
Fully Additive Fact: These are facts that can be summed up across all dimensions. For example, sales revenue can be added up by time period, by store, by product, etc.
Semi Additive Fact: These facts can be summed or averaged over some dimensions, but not all. An example is inventory levels, which can be added up across stores but not over time because doing so wouldn't make sense.
Non Additive Fact: These cannot be summed over any dimension. Examples include certain percentages or ratios, such as gross profit margin.
It is not considered as a fact column: This option suggests that the column might not be a measurement suitable for facts; however, in this context, gross profit margin is considered a fact because it is a relevant metric.
The 'Gross_Profit_Margin' is most appropriately categorized as a Non Additive Fact . This is because the gross profit margin, being a ratio of gross profit to sales revenue, cannot simply be added up across dimensions to provide meaningful insights. Instead, it is calculated after summing up the individual components (gross profit and sales revenue) if analyzed over aggregated data.
So, the correct option is:
Non Additive Fact
Understanding these distinctions helps in properly designing and using data warehouses, ensuring accurate data analysis and reporting.
Approximately 2.81 × 1 0 21 electrons flow through the electric device when a current of 15.0 A is delivered for 30 seconds. This is calculated using the relationship between current, charge, and time. Charge is divided by the elementary charge of an electron to find the total number of electrons.
;
