Answer:
c)
Step-by-step explanation:
The definition of an observational study is: one where researchers observe the effect of a risk factor or an intervention but they do not try to change who is exposed to the factor.
In this particular example, the researchers administered a questionnaire to 391 twelve-year-old and concluded that the body mass index of the adolescents who had a supply of sugary snacks in their bedroom was significantly higher than that of the adolescents who did not have a supply of sugary snacks in their bedroom.
This is not an observational study because the researchers actually administered a questionnaire and analyzed the results. To be an observational study the individuals would have been observed without any intervention (the questionnaire could have had an effect on the adolescents changing their habits)
Expression for perimeter is 2(14-x + x) = 28
<u>Step-by-step explanation:</u>
Step 1:
Given expression for area of the rectangle = a(x) = x(14-x) where x is the width. Then length = 14-x since area = length × width
Step 2:
Find expression for perimeter of the rectangle.
Perimeter of the rectangle = 2(length + width) = 2(14 - x + x) = 2 × 14 = 28
ANSWER: square root of 10
Rule: Pythagorean Theorem (a^2 + b^2 = c^2; side^2 + second side^2 = hypotenuse^2)
(substitute the missing side w/ a variable)
x^2 + 7^2 = (sqrt. 59)^2
x^2 + 49 = 59
x^2 = 10
x = sqrt. 10
Answer:
Graph
Step-by-step explanation:
Please insert a picture on the graph so this can be explained
