<h2>
Answer:</h2>
12
<h2>
Step-by-step explanation:</h2>
<u><em>The mean is also the average.</em></u>
Add up all the number of students all together:
12+13+14+9
48
Now, Divide the total amount of students (48) by the amount of numbers you added (in this case, 48/4 because we added 4 numbers wich are 12+13+14+9)
The average amount of students is 12
1,905.63 is the correct answer
Answer: 32/56, 0.57, 57% rounded = 60%
Step-by-step explanation: 8 times 7 =56 and 8 times 4= 32. our fraction is 32/56. divide 32 by 56 to make out a decimal= 0.57. Multiply 0.57 by 100 to make out a percent = 57%
D and C because that the answer
Answer:

Step-by-step explanation:
Given information: |a| = 80, |b| = 50, the angle between a and b is 3π/4.
We need to find the dot product a · b.
The formula of dot product is

where, θ is the angle between a and b.
Substitute the given values in the above formula.


![[\because \cos (\pi-\theta)=-\cos \theta]](https://tex.z-dn.net/?f=%5B%5Cbecause%20%5Ccos%20%28%5Cpi-%5Ctheta%29%3D-%5Ccos%20%5Ctheta%5D)


Rationalize the above equation.



Therefore, the value of a · b is
.