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?

Show all your work AND justify your steps.

Answer 1

She must score an 8.8 or higher

Explanation:

The average is the sum of the number divided by the number of numbers

Let x be the score on the 4th dance

The average is

( 8.9+7.1+ 9.2+x)/4

This must be at least 8.5

( 8.9+7.1+ 9.2+x)/4≥ 8.5

Multiply by 4

( 8.9+7.1+ 9.2+x)/4*4≥ 8.5*4

( 8.9+7.1+ 9.2+x)≥ 34

Combine like terms

( 25.2+x)≥ 34

Subtract 25.2 from each side

( 25.2-25.2+x)≥ 34-25.2

x≥ 8.8

She must score an 8.8 or higher