Answer:
The answer is : b) a confound
Step-by-step explanation:
While manipulating, is possible that some factors like noise in the hall, can affect learning in one of the groups but not in the other.
This possibility reflects the presence of a confound.
We can define a confounding variable as an external influencing factor which results in bringing changes in the effects of a dependent and independent variable.
This variable changes the outcome of an experiment and produces useless results.
A light-year is defined as the distance the light can cover in one year.
The light travels at speed of
, and one year converted into seconds is
So the distance covered by the light in one year is
And this is the distance that corresponds to one light-year.
Step-by-step explanation:
Could help if you showed the rest of the table
Answer:
x=9
Step-by-step explanation:
Using elimination method.
Add equation 1 to equation 2
x + y = 11
x - y = 7
---------------
2x + 0 = 18
Divide both sides by 2
2x = 18
---- ----
2 2
x = 9