Answer:
The null hypothesis is
.
The alternative hypothesis is 
Step-by-step explanation:
Suppose that a recent article stated that the mean time spent in jail by a first-time convicted burglar is 2.5 years.
At the null hypothesis, we test if the mean is of 2.5 years, that is:

A study was then done to see if the mean time has increased in the new century.
At the alternative hypothesis, we test if the mean has increased, that is, if it is above 2.5 years. So

Answer:
1. Rolling a number less than 5
The numbers on a standard dice are 1, 2, 3, 4, 5, and 6. Therefore it is possible to roll a 6, but it is much more likely to be 1-5, simply because there are more of them.
2. Rolling a 2
Again, it is more likely that the result will be one of the other 5 numbers. But obviously a 2 is still an option, so it's not impossible.
3. Rolling a number less than 10
Every option is less than 10 so it is certain.
Answer:
Variance.
Step-by-step explanation:
that is the variance of the data.
The square root of the variance is the Standard Deviation.
Answer:
(7, 0), (-8, 0), (0, 0)
Step-by-step explanation:
y = f(x) = 0
the real solutions are the ones that cross the x-axis because when a point is on the x-axis, its y coordinate will be 0.
=> (7, 0), (-8, 0), (0, 0)
Discrimination 100 the real answer is that and it will not make since at dirt but it is have a good day