Question

To get to the dance competition finals, a dancer must average at least 8.5 points on their 4 preliminary dances. The scores for Jodi’s first 3 dances were: 8.9 points, 7.1 points and 9.2 points. What is the lowest score that Jodi can get on the last dance and still make the finals?

Answer 1

Jodi must score at least 8.8 points.

Explanation:

Step 1: Given data

Score 1 (S1): 8.9

Score 2 (S2): 7.1

Score 3 (S3): 9.2

Average (Av): 8.5

Score 4 (S4): ?

Step 2: Calculate the Score 4 so that the average is 8.5

The average is equal to the sum of the scores divided by the number of scores (4).

Av = (S1 + S2 + S3 + S4)/4

4 × Av = S1 + S2 + S3 + S4

S4 = 4 × Av - S1 - S2 - S3

S4 = 4 × 8.5 - 8.9 - 7.1 - 9.2

S4 = 8.8

Jodi must score at least 8.8 points.