Post on 12-Sep-2015
description
-
, PhD
- haidich@med.auth.gr
19/10/2011
:
http://users.auth.gr/haidich/BSc/Biostatistics/
-
- 1.5-7
(kg/m2) 40 35 30 25 20 15
30
20
10
0
= =
z -4 -3 -2 -1 0 1 2 3 1
2 3
47 49 50 51 53 (kg)
48 52
68%
95%
99.7%
x
=(-)/ ~ (0,1)
Sheppard
z -4 -3 -2 -1 0 1 2 3 1
2 3
47 49 50 51 53 (kg)
48 52
68%
95%
99.7%
x
Sheppard
n=239 10-15 ,
=175,2 mg =21,2 mg
140 190 mg?
z -3 -2 -1 0 1 2 3
?
1=(140-175,2)/21,2 = -1,66
(z)=0,4515
2=(190-175,2)/21,2 = 0,69 (z)=0,2549
P(140 < x < 190)=0,4515+0,2549 = 0,7064
70,64% : 239*0,7064 = 168,8 169
P(200 < x < 220)
z -3 -2 -1 0 1 2 3
?
1=(200-175,2)/21,2 = 1,16
(z)=0,37698
2=(220-175,2)/21,2 = 2,11 (z)=0,48257
P(200 < x < 220)= 0,48257 - 0,37698 = 0,1056 10,6%
: 239*0,1056 = 25,2 25
.. 10 85
6
,
x1, x2, x3, . . ., xn s1, s2, s3, . . ., sn
N (, 2/n )
X n =
z -4 -3 -2 -1 0 1 2 3 1/n
2 /n 3 /n
47 49 50 51 53 (kg)
48 52
68%
95%
99.7%
x
( x ) =
( ) =
: ~ N (, 2/n )
Xn
X
X
X
X n =
- - Slide Number 6 Sheppard P(200 < x < 220) Slide Number 22