Question

the quality rating of 8 movies showing at a movie theater near you is 5.6, 7.9, 7.0, 5.9, 7.8, 6.2, 6.4, and 5.2. What do the ninth movies need to be for the theater to average a movie rating of 6.4?

Answer 1

5.6

Explanation:

Given :

Quality rating for 8 movies :

5.6, 7.9, 7.0, 5.9, 7.8, 6.2, 6.4, 5.2

Let rating for the 9th movie = x

Average quality rating olfor the 9 movies = 6.4

To find x :

Sum of all ratings / number of ratings = 6.4

(5.6 + 7.9 + 7.0 + 5.9 + 7.8 + 6.2 + 6.4 + 5.2 + x) / 9 = 6.4

(52 + x) / 9 = 6.4

52 + x = 57.6

x = 57.6 - 52

x = 5.6