Julie wants to have a 90 average in her math class at the end of the year. She is trying to determine what she needs to make on her final exam for this to work. Everything is weighted equally and she currently has a 85 for her quiz average, a 80 for her homework average, a 92 for her test average, and a 98 for her project average. What does she need to make on her final exam for her to end up with a 90 in the class?

Question

jacobbirddog · Answer

she needs to be a flipping genius.

anonymous · Answer

oh :3

anonymous · Answer

that's not one of my answer choices..

campbell_st · Answer

well its simply a case of summing the know marks... and knowing there average has to be 90... so 

$$90 = \frac{ 80 + 85 + 92 + 98 + x}{5}$$

solve for x, where x is the exam mark

texaschic101 · Answer

you type too fast...

texaschic101 · Answer

lol

anonymous · Answer

i don't understand

anonymous · Answer

:(

campbell_st · Answer

ok.... so you know here scores for other tasks add to 355... 

so you need to find the average of the 5 types of tasks including the exam... 


and they need to average 90

so then 

$$90 = \frac{355 + x}{5}$$

multiply both sides of the equation by 5

450 = 355 + x

campbell_st · Answer

the student needs the sum of all her assessment tasks to be 450, so she can average 90... 

so you need to solve the equation 

450 = 355 + x

x will be what's needed in the final exam.

anonymous · Answer

YES!! <3  thank you

texaschic101 · Answer

To find the average of something, you have to add up the items, then divide by how many items there are...
(80 + 85 + 92 + 98 + x) / 5 = 90 (there is 5 grades, we just don't know 1 of them)
(355 + x) / 5 = 90 --- multiply by 5
355 + x = 450
take it from here and solve for x, the final grade