So we are given that the mean is 42% and the sd (standard deviation) is 8%
Assuming our data is normal we can use the 68-95-99 rule
So one thing you should realize is that 42% + 8% is 50% which is passing. That is one standard deviation higher. So we use:
100 - 68 - 13.5 - 2.35 - 0.15 = 16. That means 16% of students passed the test. Which is terrible. They probably need to hit the books more.
Anyways if you have any question feel free to message me!
Hopes this helps!
Answer:
x = 16
y = -24
Step-by-step explanation:
Recall that the addition of matrices is done when matrices are of the same dimension. In this case, you are in fact adding matrices of the same dimension (dimension 1x2). Recall as well that in the addition of matrices, the elements of each matrix combine only with the element located in the exact same position in the other matrix.
So for this case the first element of the first matrix "16" combines with the first element of the second matrix "0" resulting in an element of value16 + 0 =16 in the new matrix.
Equally, the second element of the first matrix "-24" combines with the second element of the second matrix, resulting in : -24 + 0 = -24.
Therefore, the matrix resultant from this addition is: [16 -24] (same form of the first matrix, which indicates that adding a zero matrix to an existing matrix will not change the first matrix.
0.49 is the answer because that is <span>the approximate probability</span>
The answer is 4.85, rounded