Question

Debra has grades of 77, 95 and 81, but she also has a project to turn in. All 4 grades count equally. Write an inequality that represents the lowest grade (x) she can earn on the project to have an average of at least 82?

Answer 1

Debra already has three grades recorded and the fourth one shall be x. The avearge is expected to be at least 82, that is either 82 or above.

The average of a set of numbers is calculated as follows;

`\text{Average}=\frac{\text{Summation of data}}{Number\text{ of data}}`

With the information provided, we can now calculate as follows;

`\begin{gathered} 82=(77+95+81+x)/(4) \\ \text{Cross multiply and you'll have;} \\ 328=253+x \\ \text{Subtract 253 from both sides;} \\ 75=x \\ \text{This means the lowest grade she can have on the project would be;} \\ x\ge75 \end{gathered}`

The inequality would be

ANSWER:

`x\ge75`