Karinas science test scores for this quarter are 84,86,90 and 68. What score does she need on her fifth science test to get a test average of at least 84

Karina must score atleast 92 on the fifth test to get a average of atleast 84.

Step-by-step explanation:

We are given the following in the question:

84, 86, 90, 68

We want the average score to be atleast 84.

Let x be the score on fifth test.

Formula:

Thus, we can write the equation:

Thus, Karina must score atleast 92 on the fifth test to get a average of atleast 84.

distance covered by pamela in 9 l of fuel = 99km

let us apply unitary method here.

distance covered by pamela in 1 l of fuel =99/9 =11 km

now let us find distance covered by pamela if she has 12 l of fuel.

distance covered in 12 l = distance covered in 1 l of fuel * 12

we know that distance covered by here in 1 l is 11 km.

so distance covered in 12 l of fuel = 11*12 = 132 km.

it is contrapositive

i could not see the question too well so check yourself again too . this is because i want you to get it correct.