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

Lets take 100 and divide it by 4 to get 25, this means that 1 first part of 100 is 25 these means that the porcentage of 1 in 4 is 25%
Hope this helps
Answer:
Lisa earns more money because John makes $16 while Lisa makes $18.
Answer:

Step-by-step explanation:
The magnitude of 3D vector
can be given by the following:

Plugging in given values, we have:
.