Review Exercises

Pagano and Gauvreau (2nd Edition)

Chapter 2: Problems

2, 9, 10 and 14

Review Exercise 2.5. #2. How do ordinal data differ from nominal data?

• The categories have an order.

Review Exercise 2.5. #9. The table below categorized 10,614,000 office visits in the US by duration.

STATEMENT: Office visits are most often between 16 and 30 minutes long.

• Do you agree? (see Excel file: Chapter2-problems-pagano.xls

Duration (min) # Visits (1000s)

0 390

1-5 227

6-10 1023

11-15 3390

16-30 4431

31-60 968

61+ 185

Total 10,614

Are office visits most often between 16 and 30 minutes long?

• No- based on rates, 11-15 min has highest rate of visits. (see Excel)

Duration (min) Width # Visits (1000s)

Rate of Visit (per min)

0 1 390 390

1-5 5 227

6-10 5 1023

11-15 5 3390

16-30 15 4431

31-60 30 968

61+ ? 185

Total 10,614

Review Exercise 2.5. #9.

Evaluate Rate of visits

Review Exercise 2.5. #10.

Construct a Bar Chart (ejs10b540p03.sas) DATA d; INPUT Year cases; LABEL cases="Number of Cases";CARDS;1983 122etc;RUN;

PROC GCHART ; VBAR year / DISCRETE SUMVAR=cases; TITLE1 "Figures 1. Number of Pediatric AIDS

cases reported in the US by Year"; FOOTNOTE1 "Source: &prg"; RUN;

Figures 1. Number of Pediatric AIDS cases reported in the US by Year

Source: ejs10b540p03.sas

Number of Cases

0

1000

2000

3000

4000

Year

1983 1984 1985 1986 1987 1988 1989

Review Exercise 2.5. #14.

Construct a Percent Freq Polygon (ejs10b540p04.sas) DATA d; INPUT endpoint midpoint yr1979 yr1987; LABEL endpoint="Blood Lead (ug/dl):ENDPOINT" midpoint="Blood Lead (ug/dl):MIDPOINT" yr1979="Percent";CARDS;20 10 11.5 37.8etc ;RUN;

SYMBOL INTERPOL=JOIN;PROC GPLOT; PLOT yr1979*midpoint yr1987*midpoint

/OVERLAY ; TITLE1 "Figure 1. Initial Plot of Percent with Blood

Lead for Canadian Workers by Year"; FOOTNOTE1 "Source: &prg"; RUN;

Percent

0

10

20

30

40

Blood Lead (ug/dl):MIDPOINT

10 20 30 40 50 60 70 80 90

Figure 1. Initial Plot of Percent with Blood Lead for Canadian Workers by Year

Source: ejs10b540p04.sas

Review Exercise 2.5. #14.

Construct a Percent Freq Polygon (ejs10b540p04.sas) DATA d1; INPUT endpoint midpoint yr1979 yr1987;CARDS;0 0 0 020 10 11.5 37.8etc95 85 9.4 0.4100 100 0 0;RUN;

SYMBOL INTERPOL=JOIN;PROC GPLOT; PLOT yr1979*midpoint yr1987*midpoint

/OVERLAY ; TITLE1 "Figure 2. Percent with Blood Lead for

Canadian Workers by Year"; FOOTNOTE1 "Source: &prg"; RUN;

Percent

0

10

20

30

40

Blood Lead (ug/dl):MIDPOINT

0 10 20 30 40 50 60 70 80 90 100

Figure 2. Relative Frequency of Percent with Blood Lead for Canadian Workers by Year

Source: ejs10b540p04.sas

Percent

0

10

20

30

40

Blood Lead (ug/dl):MIDPOINT

0 10 20 30 40 50 60 70 80 90 100

Figure 2. Percent with Blood Lead for Canadian Workers by Year

Source: ejs10b540p04.sas

Review Exercise 2.5. #14.

Construct a Percent Freq Polygon (ejs10b540p04.sas) Express as rates (per 10 years)

DATA d2; SET d1; p1979=yr1979; p1987=yr1987; IF endpoint=20 THEN DO; p1979=yr1979/2; p1987=yr1987/2; END;RUN;

p1979

0

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

Blood Lead (ug/dl):MIDPOINT

0 10 20 30 40 50 60 70 80 90 100

Figure 3. Percent with Blood Lead for 10 year intervals for Canadian Workers by Year

Source: ejs10b540p04.sas

Review Exercise 2.5. #14.

Construct a Percent Freq Polygon (ejs10b540p04.sas) Express as rates (per 10 years)

DATA d2; SET d1; p1979=yr1979; p1987=yr1987; IF endpoint=20 THEN

DO; p1979=yr1979/2; p1987=yr1987/2; END;RUN;

p1979

0

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

Blood Lead (ug/dl):MIDPOINT

0 10 20 30 40 50 60 70 80 90 100

Figure 3. Percent with Blood Lead for 10 year intervals for Canadian Workers by Year

Source: ejs10b540p04.sas

Review Exercise 2.5. #14.

Construct a Cum Percent Distribution (ejs10b540p04.sas) *******************************************;*** Create cumulative percents ;*******************************************;DATA d2; SET d1; RETAIN cyr1979 cyr1987; IF _N_=1 THEN DO; cyr1979=0; cyr1987=0; END; cyr1979=cyr1979+yr1979; cyr1987=cyr1987+yr1987; LABEL cyr1979="Cum Percent 1979" cyr1987="Cum Percent 1987";RUN;

SYMBOL INTERPOL=JOIN;LEGEND1 label=none value=(h=2 font=swiss '1979' '1987') POSITION=(bottom right inside) mode=protect

cborder=black;

PROC GPLOT; PLOT cyr1979*endpoint cyr1987*endpoint /OVERLAY

LEGEND=Legend1; TITLE1 "Figure 4. Cumulative Relative Frequency of

Percent with Blood Lead for Canadian Workers by Year";

FOOTNOTE1 "Source: &prg"; RUN;

Cum Percent 1979

0

10

20

30

40

50

60

70

80

90

100

Blood Lead (ug/dl):ENDPOINT

0 10 20 30 40 50 60 70 80 90 100

Figure 4. Cumulative Relative Frequency of Percent with Blood Lead for Canadian Workers by Year

Source: ejs10b540p04.sas