**question 1\.\** the data were gathered by the following procedure, reported in the study. "between january and june 1998, parents of children aged 2-16 years that were seen as outpatients in a university pediatric ophthalmology clinic completed a questionnaire on the child’s light exposure both at present and before the age of 2 years." was this study observational, or was it a controlled experiment? explain.

OBSERVATIONAL

Step-by-step explanation:

Let`s see the two kind of experiments mentioned:

In this case, the patient's parent only answer a questionnairewith no intervention from the doctors into the pacients at all, so it's an observational  experiment

the direct variation says that:

then the equation is of the form is given by:

            where k is the constant variation.

from the given table:

consider any value of x and m(x)=y

x = 2 and m(x)=y = 3

substitute these value in [1]; we have;

divide both sides by 2 we get;

⇒

check:

put x = -1 and m(x) = -1.5

substitute in the equation:

-1.5 = -1.5                   true

therefore, the function m(x) represents a direct variation

graph of this function as shown below: