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 is the in the data table below. Complete parts (a) through (f) below.
Data:
Age, x, HDL Cholesterol, y
36 56
41 55
47 32
30 56
54 37
51 40
59 40
61 39
25 47
36 43
65 61
29 55
53 38
25 47
54 38
50 53
41 27
(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. The relation appears to be linear.
B. The relation appears to be nonlinear.
C. There does not appear to be a relation.
(b) Determine the least-squares regression equation from the sample data.
ModifyingAbove y with caret equals y=?x+? (Round to three decimal places as needed.)
(c) Are there any outliers or influential observations?
No
Yes
Use technology to compute the P-value. Use the Tech Help button for further assistance.
The P-value is (Round to three decimal places as needed.)
e) Assuming the residuals are normally distributed, construct a 95% confidence interval about the slope of the trueleast-squares regression line.
Lower Bound |
equals= |
|
Upper Bound |
equals= |
(Round to three decimal places as needed.)
(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 berecommended?
If the null hypothesis was rejected, that means that thisleast-squares regression line can accurately predict the HDL cholesterol of a patient. If the null hypothesis was not rejected, that means the least-squares regression line cannot accurately predict the HDL cholesterol of a patient.
Should this least-squares regression line be used to predict the patient's HDL cholesterol? Choose the correct answer below.
A. Yes, because the null hypothesis was rejected.
B. Yes, because the null hypothesis was not rejected.
C. No, because the null hypothesis was not rejected.
D. No, because the null hypothesis was rejected.
A good estimate for the HDL cholesterol of this patient is ? (Round to two decimal places as needed)
a)
B. The relation appears to be nonlinear
b)
Coefficientsa | |||||||
Model | Unstandardized Coefficients | Standardized Coefficients | t | Sig. | |||
B | Std. Error | Beta | |||||
1 | (Constant) | 53.585 | 8.785 | 6.100 | 0.000 | ||
Age | -0.194 | 0.190 | -0.255 | -1.021 | 0.323 | ||
a. Dependent Variable: HDL_Cholestrol |
HDL_Cholestrol = 53.585 - 0.194Age
c)
Yes
e) Assuming the residuals are normally distributed, construct a 95% confidence interval about the slope of the trueleast-squares regression line.
Coefficientsa | |||||||||
Model | Unstandardized Coefficients | Standardized Coefficients | t | Sig. | 95.0% Confidence Interval for B | ||||
B | Std. Error | Beta | Lower Bound | Upper Bound | |||||
1 | (Constant) | 53.585 | 8.785 | 6.100 | 0.000 | 34.860 | 72.310 | ||
Age | -0.194 | 0.190 | -0.255 | -1.021 | 0.323 | -0.599 | 0.211 | ||
a. Dependent Variable: HDL_Cholestrol |
Lower Bound |
equals= |
-0.599 |
Upper Bound |
equals= |
0.211 |
(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 berecommended?
If the null hypothesis was rejected, that means that thisleast-squares regression line can accurately predict the HDL cholesterol of a patient. If the null hypothesis was not rejected, that means the least-squares regression line cannot accurately predict the HDL cholesterol of a patient.
Should this least-squares regression line be used to predict the patient's HDL cholesterol?
A. Yes, because the null hypothesis was rejected
A good estimate for the HDL cholesterol of this patient is 45.437