Module 9: Using Basic Statistical Procedures

Question 1

What does PROC UNIVARIATE do?

Answer 1

It produces statistics and graphs describing the distribution of a single varaible

Question 2

Write the general syntax for PROC UNIVARIATE.

Answer 2

proc univariate;
var varlist;
plot-request varlist/ (options);
run;

plot-requestion = graph wanted to use

Question 3

List some plot-requests PROC UNIVARIATE can use.

Answer 3

CDFPLOT: cumulative distribution funciton plot
HISTOGRAM: histogram
QQPLOT: quantile-quantile plot

Question 4

List the distribution options in PROC UNIVARIATE.

Answer 4

Normal, beta, exponential, gamma, lognormal, normal, weibull

Question 5

Given the following code, explain each line.

1) proc means data = one noprint;
2) var gamedate;
3) output out = ckdate (where=(stat in (‘MIN’, ‘MAX’)));
run;

Answer 5

1) takes data from dataset one, but does not print results
2) Tells SAS to only look at gamedate
3) Puts the output to a dataset called ckdate with the condition that the observations in ckdate need to have the min and max value of gamedate

Note: need to use proc print to display the new dataset ckdate

Question 6

What does PROC CORR do?

Answer 6

It computes correlations to varaiables

Question 7

Write the general syntax to PROC CORR.

Answer 7

proc corr;
var var-list;
with var-list;
run;

Note: the with statement is optional

Question 8

What is the difference between the var and with statements in PROC CORR?

Answer 8

Var statement lists variables across the table of correlations
With statement lists variables down the side of the table

Question 9

T/F: If no with statement, then the variables in the var statement will appear both across and down.

Answer 9

True

Question 10

Fill in the blank.

The default correlations are ____ product-moment correlation coefficients.

Answer 10

Pearson

Note: can request Spearman rank with SPEARMAN option

Question 11

When doing a PROC TTEST, what is the null hypothesis to choose from variances?

Answer 11

H0: two variances equal, use pooled/equal variances
H1: two variances unequal

Question 12

Given the following code, explain each line.

proc ttest;
1) by year;
2) class league;
3) var runs;
run;

Answer 12

1) specifies seperate analysis by year
2) specifies league as a caegorical varaible
3) Specifies the variable of interest(s). A t-test will be conducted on the runs variable, comparing its means across different levles of the league