Answer:
The mean for the combined sample = 6.
Step-by-step explanation:
We have been given that one sample of n = 10 scores has a mean of M = 8.
So the sum of 10 scores for 1st sample will be: 
We are also told that second sample of n = 5 scores has a mean of M = 2.
So the sum of 5 scores for 2nd sample will be: 
When the both samples are combined, so total points will be:
and total scores will be
.



Therefore, the mean for the combined sample will be 6.
Answer:
Y = -2x and Y = |-2x| correct me
+2 crosses the equal sign to become 4y=18-2,as 18-2=16 so you get 4y=16 and finally divide both sides by 4,as 4 goes into 16,4 times,therefore,y=4
-5.55 - 8.55c + 4.35c
-8.55c + 4.35c = -4.2c
-5.55 - 4.2c is the answer.
I really think the answer is C