/* Load Data*/
FILENAME
REFFILE
'/home/u63510467/3316/ncbirth1450.csv'
;
/* import data*/
PROC IMPORT
DATAFILE
=REFFILE
DBMS
=CSV
/* data extension*/
OUT
=birth;
/* a name for you data, you can pick any name you like*/
GETNAMES
=YES;
RUN
;
/* Print Data, uncomment it if you want to print the data*/
/*proc
print DATA=birth;
run;*/
/* run t-test */
proc ttest
alpha
=
0.05
data
=birth
sides
=U
h0
=
25
;
/* alpha: significance level */
/* data: birth */
/* sides: U=right-sided, L=left-sideds, 2=two-sided */
/* h0: mu=25, null hypothesis, h1: mu>25, alternative hypothesis*/
var
mage;
run
;
/* run t-test*/
data
critical;
/*critical value in t-test*/
tc=
tinv
(
0.95
,
1449
);
/* get the critical value at confidence level C=0.95, and the freedom of t distribution is 1450*/
/* 1450 is the number of observations*/
proc print
data
=critical;
/* print the critical value*/
run
;
/* follow the procedures above to finish question (b) and (c)*/
proc ttest
alpha
=
0.95
data
=birth
sides
=L
h0
=
39
;
var
weeks;
run
;
proc ttest
alpha
=
0.95
data
=birth
sides
=U
h0
=
112
;
var
tounces;
run
;
/* side-by-side boxplot for question (d)*/
proc sgplot
data
=birth;
vbox
tounces /
category
= smoke;
title
'Tounces by smoke'
;
run
;
/* z-test for proportion in question (e) and (f)*/
/* np>=10 and n(1-p)>=10* normality test*/
proc freq
data
=birth;
tables
LOW/
binomial
(
p
=
0.06
);
run
;
proc freq
data
=birth;
tables
SMOKE/
binomial
(
p
=
0.1
);
run
;
/* please read: https://support.sas.com/kb/22/561.html */
/* you will get the idea of one-sided test and know how to deal with (h)*/
/* question (i), similar as question (h), do it yourself*/
/*CODE STARTS HERE*/
/* delete all of the null spaces*/
data
no_null;
set
birth;
if
GAINED ne
'#NULL'
;
if
WEEKS ne
'#NULL'
;
if
TOUNES ne
'#NULL'
;
if
MAGE ne
'#NULL'
;
if
SMOKE ne
'#NULL'
;
if
DRINK ne
'#NULL'
;
RUN
;
/*frequency table for % of low birth weights*/
proc freq
data
=birth;
tables
LOW /
out
=low_freq;
RUN
;
/*frequency table for the
% of smokers*/
proc freq
data
=birth;
tables
SMOKE /
out
=low_smoke;
RUN
;
/*summary table (mean, median, standard deviation, minimum, maximum)
continuous variables of mage, weeks, and tounces*/
proc means
data
=birth
mean median std max min
;
var
MAGE;
output out
=sumtab_mage;
RUN
;
proc means
data
=birth
mean median std max min
;
var
WEEKS;
output out
=sumtab_weeks;
RUN
;
proc means
data
=birth
mean median std max min
;
var
TOUNCES;
sumtab_tounces
Code: Hypotesis_test.sas
https://odamid-usw2-2.oda.sas.com/SASStudio/main?locale=en_US&z...
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8/9/23, 4:21 PM
