Answer:
i don't know maybe D. 2 and 3
Answer:
--- Standard deviation
Step-by-step explanation:
Given
See attachment for graph
Solving (a): Explain how the standard deviation is calculated.
<u>Start by calculating the mean</u>
To do this, we divide the sum of the products of grade and number of students by the total number of students;
i.e.

So, we have:



Next, calculate the variance using the following formula:

i.e subtract the mean from each dataset; take the squares; add up the squares; then divide the sum by the number of dataset
So, we have:



Lastly, take the square root of the variance to get the standard deviation


--- approximated
<em>Hence, the standard deviation is approximately 11.28</em>
Considering the calculated mean (i.e. 82.76), the standard deviation (i.e. 11.28) is small and this means that the grade of the students are close to the average grade.
Answer:
its the first answer choice!
Step-by-step explanation:
Answer:
By solving the equation
we found that 
<u>Explanation: </u>
Given equation,
to find x
Step: 1 Cross multiply the denominators 2(x-5)=6(x+6)
Step: 2 Open brackets and simplify the term 2x-10=6x+36
Step: 3 Bring x terms on one side and simplify the equation the equation obtained is following,
2x-6x=36+10
-4x=46

Therefore, we solved x value from the given equation
as
.