Reference no: EM132234483
Questions -
Q1. In Simple Linear Regression (SLR) we assume the Y-values are statistically independent of one another.
True
False
Q2. SS(X2|X1) is the extra sum of squares explained by using X2 in addition to X1 to predict Y.
True
False
Q3. F[Age, (Age)2|HGT] = ({Regression SS[HGT, Age, (Age)2] - Regression SS[HGT]}/2)/MS Residual [Age, (Age)2]
True
False
Q4. The multiple correlation coefficient, denoted as RY|X_1, X_2, . . . X_K is a measure of the overall linear association of one (dependent) variable Y with several other (independent) variables X1, X2, . . . , XK.
True
False
Q5. Answer Question a-e using the following statement and data provided.
These problems can be solved by hand or you can use SAS or any other software of your choice and provide the relevant output.
Transient hypothyroxinemia, a common finding in premature infants, is not thought to have long term consequences, or to require treatment. A study was performed to investigate whether hypothyroxinemia in premature infants is a cause of subsequent motor and cognitive abnormalities. Blood thyroxine values were obtained on routine screening in the first week of life from 536 infants who weighed 2000 g or less at birth and were born at 33 weeks gestation or earlier. The data below were presented concerning the relationship between mean thyroxine level and gestational age.
X (Gestational Age)
|
Y(Mean thyroxine Level)
|
24
|
6.5
|
25
|
7.1
|
26
|
7.0
|
27
|
7.1
|
28
|
7.2
|
29
|
7.1
|
30
|
8.1
|
31
|
8.7
|
32
|
9.5
|
33
|
10.1
|
a. What is estimated intercept and slope?
b. Interpret the estimated intercept and slope.
c. What is the predicted value of mean thyroxine level when gestational age is 28.5 weeks?
d. Provide a 97% (ninety seven percent) conÑdence interval for the s lope.
e. Is the slope of the regression line significantly different from zero H0 : β1 = 0.
Q6. Answer Questions a-b using the information below.
a. Fill in the ANOVA table.
X - Age
Y- Systolic Blood Pressure
Question Completion Status: Assume Simple Linear Regression (SLR). Show complete work. You need to fill in the value of (a, b, c, d, e, f, g, h, i)
S2Y|X = 1638.0
n = 11
S2Y = 1988.29
Analysis of Variance
|
Source
|
DF
|
Sum of Squares
|
Mean Square
|
F Value
|
Pr > F
|
Model
|
a
|
d
|
g
|
I
|
>0.05
|
Error
|
b
|
e
|
h
|
|
|
Corrected Total
|
c
|
f
|
|
|
|
b. Is there a statistically signiÑcant relationship between Age and Systolic Blood Pressure? Only answering Yes/No is not adequate. You need provide support to your answer from the ANOVA table.
Q7. A hospital operations analyst wanted to know whether the correlations between response time to patients' call and number of patients in the ward are the same for two wards. Sample data for the two wards are as follows:
Ward 1: n1 = 50, r1 = 0.62
Ward 2: n2 = 43, r2 = 0.51
Test the hypothesis that the two population correlations are equal. Use a two tailed test. What do you conclude?
Textbook - Applied Regression Analysis and Other Multivariate Methods (5th edition) Authors: Kleinbaum, Kupper, Nizam, & Muller.