Brenda’s scores on the first three of four 100-point science tests were 95, 92, and 89. What score does she need on her fourth science test to ensure an average score of at least 93?

A) X ≥ 96
B) X ≤ 90
C) X ≥ 88
D) X ≤ 92

Question

Brenda’s scores on the first three of four 100-point science tests were 95, 92, and 89. What score does she need on her fourth science test to ensure an average score of at least 93?

A) X ≥ 96
B) X ≤ 90
C) X ≥ 88
D) X ≤ 92

whpalmer4 · Answer

her average of 4 evenly weighted tests needs to be $\ge 93$

average of 4 tests = $\dfrac{test1 + test2 + test3 + test4}{4}$ We know that tests1-3 were 95,92, 89, so plug in the numbers and see what you need...

$$\frac{95+92+89+x}{4} \ge 93$$

She better study :-)

anonymous · Answer

She'll make it with 100, not much less.