class StatisticsCalculator:
    def __init__(self):
        self.results = []
    
    def calculate_average(self, numbers):
        total = sum(numbers)
        return total / len(numbers)
    
    def add_result(self, value):
        self.results.append(value)
    
    def get_statistics(self):
        if not self.results:
            return None
        return {
            "mean": sum(self.results) / len(self.results),
            "count": len(self.results)
        }