In your US History class, you have scores of 78, 89, 87 and 96 on the first four tests. To get a B, the average of the five test

Question

3 years ago

9

In your US History class, you have scores of 78, 89, 87 and 96 on the first four tests. To get a B, the average of the five test

s must be greater than or equal to 80 and less than 90. Solve an inequality to find the range of the scores needed on the fifth test to get a B

Mathematics

2 answers:

Digiron [165] · Answer 1 · 2022-07-10T15:58:10+03:00

Let x be the score of the fifth test.

a) let's find the value of x so that to get 80. To that end use the average notion:
(78+89+87+96+x)/5 = 80
(350 + x)/5 = 80. Cross multiplication
350+x = 400 and x = 50

b) let's find the value of x so that to get 90. To that end use the average notion:
(78+89+87+96+x)/5 = 90
(350 + x)/5 = 0. Cross multiplication
350+x = 450 and x = 100

Then the value of x should be:

50 < x < 100

Vaselesa [24] · Answer 2 · 2022-07-10T14:18:22+03:00

Vaselesa [24]3 years ago

3 0

Well, since it is asking for an average, we have to add
78+89+87+96=
350... then we divide by 4
which would be 87.5 which IS greater than 80 :)
and less than 90 :)