STAT Assignment

Solve the following questions:

Find the mean, mod, median, and standard deviation of the following data. And  Based on these results, check whether the value of

10

is usual?

5, 6, 7,

8

, 9,8,7,8

_______________________________________________________

2

. Pre-Employment Drug Screening Results are shown in the following Table:

Positive Test Result

Negative Test Result

Subject Uses Drugs

8

(True Positive)

2

(False Negative)

Subject is not a Drug User

10

(False Positive)

180

(True Negative)

If  1 of the 200 test subjects is randomly selected, find the probability that the subject had a positive test result, given that the subject actually uses drugs. That is,

find (positive test result ? subject uses drugs).

If 1 of the 200 test subjects is randomly selected, find the probability that the subject actually uses drugs, given that he or she had a positive test result. That is,

find ( subject uses drugs  ?  positive test result  ).

      ___________________________________________________3. 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 a 95% confidence interval based on this sample?