Answer:
5.6
Step-by-step 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
D = 1/2 * (-16). That is your answer
