Yarmouk University                          STAT 101                           Date: Aug 1 2006                                   
Statistics Department                       First Exam                        Duration: One Hour
Student Name:                                                                   Student Number:                                 
(Q1: 10 pts) Circle the correct answer in each of the following questions
1. For a set of 10 measurements with lower quartile = 6.2, upper quartile = 20.2, the median = 16.2, the distribution is considered to be
a.	symmetric	b.	right skewed	c.	left skewed	d.	all of them	

2.  The extreme values among a set of measurements will affect the
a.	Mode	b.	Mean	c.	Median	d.	all of them	

3.  If the z-score of an observation x is -3.2, then the observation is
a.	high likely	b.	likely	c.	suspect outlier	d.	an outlier	

4.  The first quartile  for the following measurements: 14, 5, 7, 11, 16, 6, 8, 19, 21, 4, 13 is 
a.	11	b.	16	c.	7	d.	6	

5. What is the median of the following set of scores 18, 6, 12, 10, 14 
a.	10	b.	14	c.	18	d.	12	

6. If the inner and outer fences are: -34, -7, 65, 92 respectively, then the observation x=100 is 
a.	Adjacent value	b.	Suspect outlier	c.	Inner fence	d.	Extreme outlier	

•	The blood types of 16 YU students are given as follows:
A, B, O, A, AB, O, A, A, AB, O, A, AB, O, B, AB, AB
Answer questions from 7 to 10
7. The experimental unit is
a.	16 students	b.	a student	c.	blood type	d.	YU	

8. The variable being measured is
a.	16 students	b.	a student	c.	blood type	d.	YU	

9. The type of these data is
a.	Qualitative	b.	Quantitative	c.	Continuous	d.	None	

10. The proportion of the blood type O is 
a.	25%	b.	0.25	c.	25	d.	None	

(Q2. 5 pts) For the equation  , use the following information 
n=10, , , Sx = 6.39, Sy = 0.43, b=0.86, to answer the following:

a.	Calculate the correlation coefficient and comment.

b.	Find the equation of the least squares line (best fitting line).

(Q3. 5 pts) The grades of 50 students have been recorded showing an average of 12 and a variance of 9. According to the empirical rule,
a. What proportion of these grades will fall between 6 and 18?

b. Approximately, how many grades will fall between 3 and 21?