public void TestGetStatistics() { // arrange var book = new InMemoryBook("", new LetterGrade()); book.AddGrade(88.1); book.AddGrade(90.6); book.AddGrade(85.6); // act var low = book.GetLow(); var high = book.GetHigh(); var average = book.GetAverage(); // asert Assert.Equal(85.6, low, 1); Assert.Equal(90.6, high, 1); Assert.Equal(88.1, average, 1); }