public function getAvgCategoriesScores(array $scores_sum_per_category, int $number_of_surveys): array 	{ 		$avg_score_per_category_array = [];  		foreach ($scores_sum_per_category as $key => $value) { 			$avg_score_per_category_array[$key] = number_format($value / $number_of_surveys, 10, '.'); 		}  		return $avg_score_per_category_array; 	}