This is observation from previous years about the impact of
students working while they are enrolled in classes, due to
students too much work, they are spending less time on their
classes. First, the observer need to find out, on average, how many
hours a week students are working. They know from previous studies
that the standard deviation of this variable is about 5 hours. A
survey of 200 students provides a sample mean of 7.10 hours worked.
What is...