7.2
Work: 45% x 16=
(45/100) x 16=
(45x16) / 100=
720/100=
7.2
Answer:
x = -18
Step-by-step explanation:
Isolate the variable, x. Note the equal sign, what you do to one side, you do to the other.
Multiply 2 to both sides:
(x/2) * 2 = (-9) * 2
x = -9 * 2
x = -18
x = -18 is your answer.
~
40 miles an hour and yeah..
Answer: C is correct, No solution
Step-by-step explanation:
Let’s simplify the second equation,
8x-4y=-20
We can divide the whole equation by 4...
8x/4-4y/4=-20/4
Which becomes....
2x-y=-5
Now let’s move things around to see if it’s the same equation as the one on top...
-y=-2x-5
y=2x+5
Now we need to solve the systems...
y=2x-5
y=2x+5
Since their slopes are both 2 and their y-intercepts are not identical, the answer is no solution. The two lines will continue on without ever crossing because they have the same slope.
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.