Math Is Fun Forum

alfakaks

Guest

I dont know how to solve it

I add picture of my exercise and I add sample too. Please somebody solve this exercise and add this here or send to my e-mail: alfakaks@gmail.com
I am a chemistry student and can not remember the math any more.
This exercise is very important for me, many thanks to helper!

alfakaks

Guest

Re: I dont know how to solve it

Exercise is here:

alfakaks

Guest

Re: I dont know how to solve it

Anobody help me?

Kejik

Member

Registered: 2010-03-03

Posts: 5

Re: I dont know how to solve it

In a mathematics test, the mean score was 62. When the marks of four student who were absent for the test were added, the new class mean calculated for the test was 66. What was the average test score for these four students if the total number for students in class was 27?

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: I dont know how to solve it

Hi Kejik;

So 23 students altogether if their grades were added scored 1426

When 4 more students were added the total grades if they were all added together was

66 * 27 :

1426 + x = 66 * 27 where x is how many total grade points the 4 students added.

x = 356

Now this is divided among the 4 added students.

356 / 4 = 89. the four new students averaged 89.

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In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

alfakaks

Guest

Re: I dont know how to solve it

Now I know the right answers, but I need solution- how do I get i = dq / dt. I writed right answer for i, but i need solution.