In: Statistics and Probability
A doctor wanted to determine whether there is a relation between a male's age and his HDL (so-called good) cholesterol. The doctor randomly selected 17 of his patients and determined their HDL cholesterol. The data obtained by the doctor are in the accompanying data table. Complete parts (a) through (f) below.
1. Click the icon to view the data obtained by the doctor.
2. Click the icon to view the Student's t-distribution table.
(a) Draw a scatter diagram of the data, treating age as the explanatory variable. What type of relation, if any, appears to exist between age and HDL cholesterol?
A. There does not appear to be a relation.
B. The relation appears to be nonlinear.
C. The relation appears to be linear.
(b) Determine the least-squares regression equation from the sample data.
y = _____ X + _____
(Round to three decimal places as needed.)
(c) Are there any outliers or influential observations?
Yes
No
(d) Assuming the residuals are normally distributed, test whether a linear relation exists between age and HDL cholesterol levels at theα=0.01 level of significance.
What are the null and alternative hypotheses?
A.
H0: β=0
H1: β=/=0
B.
H0: β=0
H1: β>0
C.
H0: β=0
H1: β<0
D.
H0: β=/=0
H1: β=0
Calculate the test statistic.
t0=_____
(Round to two decimal places as needed.)
Determine the range of the P-value for this hypothesis test. Choose the correct answer below.
A.The P-value is less than 0.001
B.The P-value is between 0.3 and 0.4
C.The P-value is between 0.4 and 0.5
D.The P-value is between 0.1 and 0.2
What conclusion can be drawn at alphaαequals=0.01 level of significance?
A.
Reject the null hypothesis because the P-value is greater than or equal to α=0.01
B. Reject the null hypothesis because the P-value is less than α=0.01
C. Do not reject the null hypothesis because the P-value is less than α=0.01
D. Do not reject the null hypothesis because the P-value is greater than or equal to α=0.01
(e) Assuming the residuals are normally distributed, construct a 95% confidence interval about the slope of the true least-squares regression line.
Lower Bound = _____
Upper Bound = _____
(f) For a 42-year-old male patient who visits the doctor's
office, would using the least-squares regression line obtained in
part (b) to predict the HDL cholesterol of this patient be
recommended?(Round to three decimal places as needed.)
Should this least-squares regression line be used to predict the patient's HDL cholesterol?
A. No, because the confidence interval about the slope of the true least-square regression line indicates that there is a linear relationship between age and HDL cholesterol levels.
B. Yes, because the hypothesis test indicates that there is a linear relationship between age and HDL cholesterol levels.
C. No, because the hypothesis test indicates that there is not a linear relationship between age and HDL cholesterol levels.
D. Yes, because the confidence interval about the slope of the true least-square regression line indicates that there is a linear relationship between age and HDL cholesterol levels.
A good estimate for the HDL cholesterol of this patient is _____
(Round to two decimal places as needed.)
1: Age vs. HDL Cholesterol data
Age, x |
HDL Cholesterol, y |
Age, x |
HDL Cholesterol, y |
|
---|---|---|---|---|
40 |
57 |
37 |
46 |
|
41 |
52 |
64 |
61 |
|
48 |
33 |
30 |
54 |
|
30 |
56 |
51 |
34 |
|
57 |
35 |
29 |
45 |
|
53 |
39 |
50 |
39 |
|
60 |
42 |
48 |
54 |
|
59 |
38 |
41 |
26 |
|
25 |
47 |