Do you believe in ratings? Either it will be Google, Facebook, Yellow Pages, or YELP. Rating for your business greatly affected by the ratings you receive online. I have made a tool for a client, where any registered customer come and check their cumulative ratings and put expected ratings in the textbox and the small Algo code behind will show them:

How many 5 Stars they need to meet their expected ratings

Here below is the code behind:

Ratings View Model contains following properties

...
public double AverageRatings{get; set;}
public double ExpectedRatings{get; set;}
...

Below is the method you will call and get the expected numbers of 5 Stars you need to meet your expected ratings as an output.

public int GetTargetRating(RatingsViewModel model)
        {
            double avg = model.AverageRatings;
            double expected = model.ExpectedRatings;
            if (expected > 4.9) expected = 4.9;
            double _sum = 0;
            int count = 1;
            while ( avg < expected)
            {
                avg = model.AverageRatings;
                for(int i=0; i< count; i++)
                {
                    _sum += 5.0;
                }
                avg = (avg + _sum) / (count+1);
                count++;
                _sum = 0;
            }
            return count;
        }

Hope you will find it useful, keep sharing and supporting 🙂