public void BookCalculatesAnAverageGrade() { //arrange var book = new Book(""); book.AddGrade(89.1); book.AddGrade(90.5); book.AddGrade(77.5); //act var result = book.GetStatistics(); //assert Assert.Equal(85.7, result.Average, 1); Assert.Equal(90.5, result.High, 1); Assert.Equal(77.5, result.Low, 1); }