Answer
D or the fourth one because i took the quiz and got it right
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.
First we need to make both fractions equal to each other, and that means having to have the denominators the same.
What both 3 and 12 easily go into is 12.
So we need to make both fractions have a denominator of 12, so we multiply.
2/3 * 4/4 = 8 / 12
1/4 * 3/3 = 3 / 12
Now, we know that she has 8 / 12 pounds, and she uses 3 / 12 of it, so now we subtract to find how much she has left.
8 - 3 = 5
Out of the 12 pounds of roast beef, she now has 5 / 12 left.
Answer:
Max exercises 13 hours a week, and Sasha 7.
Step-by-step explanation:
To find the number of hours each of them exercises during the week, we solve the system of equations.
In the second equation:
Replacing in the first equation:
So Sasha exercises 7 hours per week.
Max:
Max exercises 13 hours a week.
Answer:
The equation is 
Step-by-step explanation:
The parameter that we have is t. We want to eliminate this parameter in both equations, therefore in the first equation we solve for t and in the second equation we solve for the variable t.
We have:
Now we solve the other equation for t.
<em> because</em> 
As 
and also 
Then:
