Step-by-step explanation:
A compound contains atoms of different elements chemically combined together in a fixed ratio. An element is a pure chemical substance made of same type of atom. ... Compounds contain different elements in a fixed ratio arranged in a defined manner through chemical bonds. They contain only one type of molecule.
Answer:
2 5/6
Step-by-step explanation:
9 5/12 - 6 7/12
We will need to borrow from the 9
8 12/12 + 5/12 - 6 7/12
8 17/12 - 6 7/12
(8-6) + (17/12 -7/12)
2 10/12
This simplifies. Divide the top and bottom of the fraction by 2
2 5/6
From trigonometry we know that:
if 
then, 
(where 
is an integer)
This can be rewritten in degrees as:
.............(Equation 1)
Now, in our case, 
Therefore, (Equation 1) can be written as:
..........(Equation 2)
Now, to find the correct options all that we have to do is replace n by relevant integers and find the values of 
that match.
For n=2, (Equation 2) gives us: 
.
Thus, 
Now, we know that: 
Let n=-1, then:
Thus, 
Likewise, 
Only the last option 
will never match 
because no integral value of will ever give 
Thus the last option is the correct option.
Answer:
25% on question one
Step-by-step explanation:
For example, on question one, 5 students drink more than half a dozen sodas a week. If there is a total of 20 students you'd divide 5 by 20 and that should be the answer.
Option 1:
<span>Measuring the heights of every fiftieth person on the school roster to determine the average heights of the boys in the school
</span>
Comment: this might not be a good idea for fairness as we only wish to determine average height of the boys. Taking a group of 50 people randomly, might not give us the same number of boys every time.
Option 2:
<span>Calling every third person on the soccer team’s roster to determine how many of the team members have completed their fundraising assignment
Comment: The context doesn't seem to need a sampling. The number of players in a soccer team is considerably small. We can find exact data by asking in person.
Option 3:
</span><span>
Observing every person walking down Main Street at 5 p.m. one evening to determine the percentage of people who wear glasses
</span>
Comment: To get a more accurate result and fairer sampling, the period of observing could have been longer, for example, observing for 12 hours on that day, or an alternative is to observe at 5 pm for 7 days in a row. It could happen that no one walking down the Main street precisely at 5 pm wears glasses, or it could happen the other way around.
Option 4:
<span>Sending a confidential e-mail survey to every one-hundredth parent in the school district to determine the overall satisfaction of the residents of the town taking a poll in the lunch room (where all students currently have to eat lunch) to determine the number of students who want to be able to leave campus during lunch.
Comment: This sampling does fairly represent the population, although it might be an idea to scale down the sample population, i.e. every fiftieth parent.
Answer: Option 4</span>
