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)
Answer:
$780
Step-by-step explanation:
P = Original Price
P (100% - 10%) = $702
P (90%) = $702
(P (.9)) / .9 = $702 / .9
P = $780
Check answer:
$780 (90%) = $702
Answer:
(-5 , 1)
Step-by-step explanation:
because this point lies in the shaded region.
−10+1≤3x≤1+1
2 Simplify.
−9≤3x≤2
3 Divide the whole equation by 3.
9/3 ≤x≤ 2/3
4 Simplify.
−3≤x≤ 2/3
-3<x<4
Answer:
OK
Step-by-step explanation:
The first screenshot is for #7 and the second screenshot is for #8
