In your biology class, your final grade is based on several things: a lab score, scores on two major tests, and your score on the final exam. There are 100 points available for each score. However, the lab score is worth 21% of your total grade, each major test is worth 22.5%, and the final exam is worth 34%. Compute the weighted average for the following scores: 81 on the lab, 75 on the first major test, 97 on the second major test, and 84 on the final exam.

The weighted average for the given scores is 84.27

Step-by-step explanation:

The weighted average can be calculated from the formula

Weighted average =

Where w is the weight

and x is the score

The scores are 81, 75, 97, and 84 while their respective weights are 21% (0.21), 22.5%(0.225), 22.5%(0.225), and 34%(0.34).

From the formula

Weighted average =

Since we have four sets of values, we can write that

Weighted average = =

Let 81, 75, 97, and 84 be and respectively; then

0.21, 0.225, 0.225, and 0.34 will be and respectively.

∴ Weighted average =

Weighted average =

Weighted average = 84.27

Hence, the weighted average is 84.27

pay attention in your classes and concentrate the best thing you can do to raise your test scores is to pay attention when you're supposed to be learning the material: in class!

take good notes.

do your homework.

use mnemonics and other tricks.

do practice tests.

note: the best i know.

the answer to this question is 3/19

step-by-step explanation: