No matter how you get your data together (and this is one of the strengths of the Power Suite) you then need to build a model, while Excel will give you the most limited viewing options they are still there and this rapidly becomes a significant timesaver.
While this did end up being a longer video that intended the content is great for understanding what it takes to manage finish of your report. Getting your data in the right shape is so often half the battle, as most analytics and reporting relates to simple aggregations with different filters, Power BI is built around that concept, so for the free report available below only two measures were use a count and an average.
Businesses = COUNTROWS( FoodHygieneRatings )
AVG Hygiene = AVERAGEX ( FoodHygieneRatings, LOOKUPVALUE ( RatingImage[Ordinal], RatingImage[RatingKey], FoodHygieneRatings[RatingKey] ) )
With those two measures in place the rest falls into place, after all, what more do you need than to know the number of businesses and the average score?