9.18
a) Using forward stepwise regression to find the best subset of predictor variables to predict job proficiency. The Alpha-to-Enter significance level was set at 0.05 and the Alpha-to-Leave significance level was set at 0.10. The first predictor entered into the stepwise model is X3. SAS tells us that the estimated intercept is -106.13 and the estimated slope for X3 is 1.968. The R2-value is 0.8047, mean square error is 76.87. The second predictor entered into the stepwise model is X1. The estimated intercept is -127.596, the estimated slope for X1 is 0.3485 and the slope for X3 is 1.8232. The R2-value is 0.933 and the mean square error is 27.575. The final predictor entered is X4. The estimated intercept is -124.20, the estimated slope for X4 is 0.5174, the slope for X1 adjusts to 0.2963 and the slope for X3 adjusts to 1.357. The R2-value is 0.9615 and the mean square error is 16.581. Predictor X2 is not eligible for entry into the stepwise model because its t-test P-value doesn’t meet the 0.05 significance level. We prefer the model containing the three predictors X3, X1 and X4, because its R2-value is 0.9615, which is higher than 0.9330 (the model containing just two predictors X3 and X1) and 0.8047(the model containing just one predictor X3). Checking the mean square error of the three models we find that the model we selected as best model has the smallest mean square error 16.581, which is good. To sum up, using forward stepwise regression, the best model to predict the job proficiency is Y= -124.20 + 0.2963X1 + 1.357X3 + 0.5174X4, a model containing predictor variables X1, X3 and X4.

b) Compare the best subset obtained from forward stepwise regression with that obtained from the adjusted R-square value criterion.

Above is the SAS output of the Adjusted R-Square Selection Method. According to the adjusted R-square value criterion, the best model should be the model with...

...greater increase in days in the hospital as drug count and visit count increase. In comparison, patients age 40 and over spend a less number of days in the hospital.
The remainder of our analysis will focus on H6 & H7.
Methods: Descriptive Statistics
1. Demographics of Data Collection and Operationalization of the Variables
The study population consists of:
PEOPLE AGES (at the first time of service):
* 0-39 years old
DRUG COUNT: Number of Drugs Administered at...

...
November 19, 2010
NAME: The Statistics of Poverty and Inequality
TYPE: Sample
SIZE: 97 observations, 8 variables
DESCRIPTIVE ABSTRACT:
For 97 countries in the world, data are given for birth rates, death
rates, infant death rates, life expectancies for males and females, and
Gross National Product.
SOURCES:
Day, A. (ed.) (1992), _The Annual Register 1992_, 234, London:
Longmans.
_U.N.E.S.C.O. 1990 Demographic Year Book_ (1990), New York: United
Nations.
VARIABLE...

...(SY16C) -INTRODUCTORY STATISTICS FOR THE
BEHAVIOURAL SCIENCES
SUMMER SCHOOL 2012/2013- COURSE OUTLINE
Lecturer: Ayesha Facey
Office: Room 46, Faculty of Social Sciences
Office #: 970-6324
E-mail: ayeshafcy@yahoo.com
COURSE OBJECTIVE
This course aims to introduce students to basic univariate and bivariate statistics. A student who successfully completes this course will possess a reasonable level of knowledge of basic...

...SECTION A (You should attempt all 10 questions)
A1. Regression analysis is ____________________________________.
A) describes the strength of this linear relationship.
B) describes the mathematical relationship between two variables.
C) describes the pattern of the data.
D) describes the characteristic of independent variable.
A2. __________________ is used to illustrate any relationship between two variables.
A) Histogram
B) Pie chart
C) Scatter diagram...

...Chapt 10 # 42
H0: game length is >= 3.5 hours
Ha: game length is < 3.5 hours
mean = 2.9553
stdev = 0.5596
Get the t test statistic:
t = (x-mu)/(stdev/sqrt(N))
t = (2.9553-3.5)/(0.5596/sqrt(17))
t = -4.0133
Get the critical value for df = N-1 = 16, one tail, alpha is 0.05:
-1.7459
Since our test statistic is much lower than the critical value, we reject the null hypothesis. There is enough evidence to conclude that games are shorter than 3.50...

...Statistics 1
Business Statistics
LaSaundra H. – Lancaster
BUS 308 Statistics for Managers
Instructor Nicole Rodieck
3/2/2014
Statistics 2
When we hear about business statistics, when think about the decisions that a manager makes to help make his/her business successful. But do we really know what it takes to run a business on a statistical level? While some may think that business...

...evidence there is against the null hypothesis that [pic].
The statistic
|[pic] |
can be used to test the hypothesis that [pic] for the two variables. It turns out that, if the two variables have a bivariate normal distribution and the null hypothesis is true, then this statistic follows a t distribution with [pic]degrees of freedom. For a fixed sample size [pic], the farther that the value of this statistic is from...

...CLICK TO DOWNLOAD
BUS 308 STATISTICS FOR AMANAGERS
BUS 308 Week 1 DQ 1 Language
Numbers and measurements are the language of business.. Organizations look at results, expenses, quality levels, efficiencies, time, costs, etc. What measures does your department keep track of ? How are the measures collected, and how are they summarized/described? How are they used in making decisions? (Note: If you do not have a job where measures are available to you, ask someone you know for...