Question

Your grades on 4 math tests are 79, 85,

Answer 1

Answer:

The grade on the fifth test that will give you a mean score of at least 85 is 87

Step-by-step explanation:

From the question, the grades on 4 math tests are 79,85,86, and 88.

To determine the grade on the fifth test that will give a mean score of at least 85,

Let the grade on the fifth test be x,

From the formula for mean

Mean = Sum of terms / Number of terms

That is,

85 = (79 + 85 + 86 + 88 + x) / 5

$85 = \frac{79 + 85 + 86 + 88 + x}{5}$

$85 = \frac{338 + x}{5}$

$338 + x = 85 \times 5$

$338 + x = 425$

$x = 425 - 338$

$x = 87$

x = 87

Hence, the grade on the fifth test that will give you a mean score of at least 85 is 87.