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

452,489 to the nearest thousand is 452,000

16.9 times 2.85

step-by-step explanation: