Step-by-step explanation:
I don't recognize this problem, please make sure the input is complete.
The answer is C.
You want:
10 < a < 14 (greater or equal)
The difference between 10 and 12 is 2.
The difference between 12 and 14 is 2.
Therefore the absolute value allows you to express that the difference between a and 12 cannot be greater than 2 (either going up to a max of 14 or going down to a minimum of 10).
Answer:
There is not sufficient evidence to support the claim that the technique performs differently than the traditional method.
Step-by-step explanation:
The null hypothesis is:

The alternate hypotesis is:

The test statistic is:

In which X is the sample mean,
is the value tested at the null hypothesis,
is the standard deviation and n is the size of the sample.
A researcher used the technique with 260 students and observed that they had a mean of 94 hours. Assume the standard deviation is known to be 6.
This means, respectively, that 
The test-statistic is:



The pvalue is:
2(P(Z < -2.69))
P(Z < -2.69) is the pvalue of Z when X = -2.69, which looking at the z-table, is 0.0036
2*(0.0036) = 0.0072
0.0072 < 0.01, which means that the null hypothesis is accepted, that is, there is not sufficient evidence to support the claim that the technique performs differently than the traditional method.