Answer:
B. The observational study is a cross-sectional study because information is collected at a specific point in time.
Step-by-step explanation:
1) There are three types of Observational Studies: Case-control, cross-sectional and Cohort.
2) Since the researchers collected information from those 1800 adults at a certain time, then we can call it a cross-sectional study. It does not provide solid results since the research was not done over a period to collect further information. We don't know, for example, much more than what that association deeply mean.
3) If we wonder more, then the researchers would have to track those adults over a given period, i.e. a Cohort would be necessary.
4) Moreover, it's not "retrospective" for virtually every question, always makes us look back somehow, and it does not categorize a kind of observational study.
Answer:
the value of x would be 5.5
Step-by-step explanation:
This is true by multiplying 2 by 5 and a half
The object should be placed 20/cm from the lens so as to form its real image on the screen
<h3>Mirror equation</h3>
The mirror equation is given according to the expression below;
1/f = 1/u + 1/v
where
f is the focal length
u is the object distance
v is the image distance
Given the following parameters
f = 5cm
v = 20cm
Required
object distance u
Substitute
1/5 = 1/u +1/20
1/u = 1/5-1/20
1/u = 3/20
u = 20/3 cm
Hence the object should be placed 20/cm from the lens so as to form its real image on the screen
Learn more on mirror equation here; brainly.com/question/27924393
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Answer:
the slope -3, slope meaning rate of change and y intercept is 1.
hope that answers your question
(used desmos to graph, good stuff!!!)
