Review Question for Stat

Review Questions for the Midterm Exam

Part I. All the Homeworks and Quizzes (50% of the Midterm Exam)

Part II. Additional Review Questions

1. Which of the following statements is correct?
a) The range is a measure of central tendency.
b) The median is a measure of dispersion.
c) For a symmetric distribution, the mean is equal to the median.
d) For a skewed distribution, the variance is a negative number.
e) The variance is a measure of central tendency.

2. After a test, John found out that she scored in the 80th percentile. This means
a) John scored as high or higher than 20% of the students who took the test.
b) At least 80% of the students who took the test did better than John.
c) John scored as high or higher than 80% of the students who took the test.
d) John answered 80% of the questions correctly.
e) None of the above

3-5. The probability that Mary will play soccer is 0.3, the probability that Wendy will play soccer is 0.4, and they make their decisions independently.

3. The probability that both of them will play soccer is
a) .28
b) .18
c) .1
d) .42
e) .12

4. The probability that Mary or Wendy or both will play soccer is
a) .58
b) .82
c) .7
d) .12
e) None of these

5. The probability that both Mary and Wendy will not play soccer is
a) .58
b) .82
c) .18
d) .42
e) .12

6-8. A survey classified 200 students by gender and by their opinion on a certain issue. The number falling into the different categories are shown in the following table. A student is randomly chosen from the group. Opinion
Gender For Against Total
Male 30 40 70
Female 50 80 130
Total 80 120 200

6. The probability that the student is female and is against the issue is
a) .615
b) .4
c) .667
d) .85
e) None of these

7. The probability that the student is male or is for the issue is
a) .35
b) .40