Introductory Biostatistics

TABLE E7.22

Exposed Nonexposed

DBP (mmHg) n Mean SD n Mean SD

< 95 205 220 50 271 221 42

95–100 92 227 57 53 236 46

b 100 20 233 41 10 216 48

7.23 When a patient is diagnosed as having cancer of the prostate, an impor-
tant question in deciding on treatment strategy is whether or not the
cancer has spread to the neighboring lymph nodes. The question is so
critical in prognosis and treatment that it is customary to operate on the
patient (i.e., perform a laparotomy) for the sole purpose of examining

TABLE E7.23

X-

ray Grade Stage Age Acid Nodes

X-

ray Grade Stage Age Acid Nodes

01 16440000 060780

00 16340000 052830

10 06546000 167950

01 06747000 056980

0 0 0 66 48 0 0 0 1 61 102 0

0 1 1 65 48 0 0 0 0 64 187 0

00 06049010 158481

00 05149000 165491

00 06650011 157511

00 05850001 050561

01 05650011 067671

00 16150000 167671

01 16450001 157671

00 05652001 145701

00 06752000 146701

10 04955010 151721

01 15255011 160761

00 06856011 156781

01 16659011 150811

10 06062000 056821

00 06162000 163821

11 15963011 165841

00 05165010 164891

01 15366001 059991

0 0 0 58 71 0 1 1 1 68 126 1

0 0 0 63 75 0 1 0 0 61 136 1

00 153760

Note:This is a very long data file; its electronic copy, in a Web-based form, is available

from the author upon request.

280 COMPARISON OF POPULATION MEANS