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.
The third one duhhh, Ik this stuff
Answer:

Step-by-step explanation:
Remove the parentheses and take out the constansts.

Simplify 7 x 3 to 21.

Use the product rule: 

Simplify 2+5 to 7.

Simplfiy 3 + 8 to 11.

Answer:
Dependant variables- how much fertiliser depends on the size of the lawn
Independent variables- Gardeners will always buy fertiliser.
Step-by-step explanation: