STAT 200: Introduction to Statistics

Final Examination, Fall 2015 OL1/US1

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STAT 200
OL1/US1 Sections
Final Exam
Fall 2015
The final exam will be posted at 12:01 am on October 9, and it is due at 11:59 pm on October 11, 2015. Eastern Time is our reference time.

This is an open-book exam. You may refer to your text and other course materials as you work on the exam, and you may use a calculator. You must complete the exam individually. Neither collaboration nor consultation with others is allowed.
Answer all 25 questions. Make sure your answers are as complete as possible.
Show all of your work and reasoning. In particular, when there are calculations involved, you must show how you come up with your …show more content…

The five-number summary below shows the grade distribution of two STAT 200 quizzes for a sample of 500 students.
Minimum
Quiz 1
Quiz 2

Q1

Median

Q3

Maximum

15
20

45
35

55
50

85
90

100
100

For each question, give your answer as one of the following: (a) Quiz 1; (b) Quiz 2; (c) Both quizzes have the same value requested; (d) It is impossible to tell using only the given information. Then explain your answer in each case.
(4 pts each)
8.
9.
10.

Which quiz has less interquartile range in grade distribution?
Which quiz has the greater percentage of students with grades 90 and over?
Which quiz has a greater percentage of students with grades less than 60?

Refer to the following information for Questions 11, 12, and 13. Show all work. Just the answer, without supporting work, will receive no credit.
There are 1000 students in a high school. Among the 1000 students, 800 students have a laptop, and 300 students have a tablet. 150 students have both devices.
11.
12.
13.

14.

What is the probability that a randomly selected student has neither device?
(10 pts)
What is the probability that a randomly selected student has a laptop, given that he/she has a tablet?
(5 pts)
Let event A be the selected student having a laptop, and event B be the selected student having a tablet. Are A and B independent events?