Complex SQL or Eloquent query - mysql

Question

I have this Database schema
exercise_quiz table
CREATE TABLE `exercise_quiz` (
`exercise_id` int(10) unsigned NOT NULL,
`quiz_id` int(10) unsigned NOT NULL,
`user_id` int(10) unsigned NOT NULL,
`answer` varchar(191) COLLATE utf8mb4_unicode_ci NOT NULL,
`created_at` timestamp NULL DEFAULT NULL,
`updated_at` timestamp NULL DEFAULT NULL,
PRIMARY KEY (`exercise_id`,`quiz_id`,`user_id`),
KEY `exercise_quiz_user_id_foreign` (`user_id`),
KEY `exercise_quiz_quiz_id_foreign` (`quiz_id`),
CONSTRAINT `exercise_quiz_exercise_id_foreign` FOREIGN KEY (`exercise_id`) REFERENCES `exercises` (`id`) ON DELETE CASCADE,
CONSTRAINT `exercise_quiz_quiz_id_foreign` FOREIGN KEY (`quiz_id`) REFERENCES `quizzes` (`id`) ON DELETE CASCADE,
CONSTRAINT `exercise_quiz_user_id_foreign` FOREIGN KEY (`user_id`) REFERENCES `users` (`id`) ON DELETE CASCADE
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;
exercises table
CREATE TABLE `exercises` (
`id` int(10) unsigned NOT NULL AUTO_INCREMENT,
`title` varchar(191) COLLATE utf8mb4_unicode_ci DEFAULT NULL,
`body` text COLLATE utf8mb4_unicode_ci NOT NULL,
`created_at` timestamp NULL DEFAULT NULL,
`updated_at` timestamp NULL DEFAULT NULL,
`course_id` int(10) unsigned NOT NULL,
`score` int(11) DEFAULT NULL,
PRIMARY KEY (`id`),
KEY `exercises_course_id_foreign` (`course_id`),
CONSTRAINT `exercises_course_id_foreign` FOREIGN KEY (`course_id`) REFERENCES `courses` (`id`) ON DELETE CASCADE
) ENGINE=InnoDB AUTO_INCREMENT=145 DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;
quizzes table
CREATE TABLE `quizzes` (
`id` int(10) unsigned NOT NULL AUTO_INCREMENT,
`question` varchar(191) COLLATE utf8mb4_unicode_ci NOT NULL,
`created_at` timestamp NULL DEFAULT NULL,
`updated_at` timestamp NULL DEFAULT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=3 DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;
Example of data in exercise_quiz
How can I retrieve this, either with raw SQL or with Eloquent, in such a way as I’d have one single row for each exercise_id with one column with the average answer for each quiz_id ? something like
exercise_id --- avg_quiz_1 ---- avg_quiz_2 ---- avg_quiz_3 ...