STAtistics / Mr. Hansen
Test #2, 10/8/2009 (Text through p. 113, all class work)

Name: _______________________

General Instructions: Raise your hand if you have a question. Write answers in the space provided. If you need additional room, write "OVER" and use reverse side.

Part I. Terminology (2 pts./box, 28 pts. total).
Fill in the blank boxes. The first row has been filled in as an example.

#

Description

Customary Name

Notation

(1.)

The number that forms the right edge of the box (not the whisker) in a boxplot

third quartile

Q3

2.

Number of data points (observations)

 

 

3.

The measure of spread (a.k.a. dispersion) that is defined by Q3 − Q1

 

 

4.

Sample standard deviation

sample s.d.

 

5.

One interpretation of the concept of “average” (i.e., central tendency)

 

M or Q2

6.

The sum of the values in a univariate quantitative sample, divided by the sample size

 

 

7.

The 25th percentile of a distribution of data values

 

 

8.

A measure of how well the data points in a scatterplot “stick” to the linear regression model

 

 

9.

Size of population

population size

 

10.

Computed LSRL slope (on the AP exam)

LSRL slope

 

 

Part II. Creative Answers (8 pts. each, 16 pts. total).
Categorize each of the following distributions as uniform, symmetric, skew left, skew right, normal, or other. Then provide a believable chart of the type requested. You will need to fabricate some data in a believable manner.

11.

Consider the distribution of heights (inches) in adult males.

What type of distribution is this? NORMAL
Draw a believable sample stemplot with split stems, where n = 20:

 

 

 

 

 

 

 

 

 

 

 

 

 

12.

Consider the distribution of rolls when two fair dice are rolled at the same time.

What type of distribution is this? _____________________

In the space to
the right, make
a rough sketch
of a histogram
and indicate
relative frequency or units
on the axes: 

Section III. Free Response (12 pts. each).
Use your knowledge of statistical methods and the graphing calculator to solve the following problems.

13. (a) Define the concept of bias in the context of our statistics class.



    (b) Give an example of bias in a survey. Give the name of the type of bias shown.

 

 

14. In 2008 and 2009, the College Board reported the following AP Statistics results:

 

Score

 

Number (2008)

 

Number (2009)

 

1 (not qualified)

 

14,009

 

14,353

 

2 (not qualified)

 

24,528

 

26,050

 

3 (pass)

 

25,707

 

28,276

 

4 (pass)

 

20,403

 

22,283

 

5 (high pass)

 

23,637

 

25,914

(a)  Compute the percentages at each grade level, and add two columns to the table.

(b)  Explain why paired pie graphs do not do a particularly good job of comparing the results for 2008 with the results for 2009.

      __________________________________________________________

(c)  Make a paired 100% graph for comparing the results for 2008 with the results for 2009.

 

 

 

 

 

 

 

 

15. One type of bias (non-statistical) is a conflict of interest. Explain two ways in which conflicts of interest may have played a pivotal role in the financial catastrophe of 2008-2009.

 

 

16. Compute the r value (r = __________ ) and regression line ( _________________ ) for the following data set. Is your LRSL fit appropriate to this data set? ____ Why or why not? ____________________________________ Support your answer adequately.

 

x

y

 

1

13

 

2

14

 

3

15

 

4

16.2

 

9

17

 

11

18

 

12

19

 

 

 

 

 

 

 

 

 

17. Fill in the blanks: For univariate graphical display, our chief tools are ___________

___________________________________________________________________

___________________________________________________________________

___________________________________________________________________ .

(List as many as you can think of.)

For bivariate graphical display, our chief tool is the ___________________ .