Answer: 83.3
Step-by-step explanation:
Formula :
(1)
(2)
Given : In a psychology class, 32 students have a mean score of 93.2 on a test.
By Using (2) , Sum of scores of 32 students = 93.2 x 32 =2982.4 (3)
Then 16 have a mean score of 63.4.
Again, By Using (2) , Sum of scores of 16 students = 63.4 x 16 =1014.4 (4)
Total students = 32+16 = 48
Add (3) and (4) , we get combined score of 48 students = 2982.4+ 1014.4
=3996.8
Now , by using (2) , the mean score of all of these students together

Hence, the mean score of all of these students together is 83.3.
I'm pretty sure its the 3rd one
Answer:
(2,-3)
Step-by-step explanation:
I used substitution and rearranged the second equation to y=-2x+1. Then I replaced the y in the first equation with -2x+1. So, I got 3x-5(-2x+1)=21. When you solve that you get 13x=26 or x=2. Then you replace x with 2 in either equation and end up with y=-3.
Solve for
:

Now if
, we have
and

On the other hand, if
, then
and
