Assignment 1:
It is evident from the medical literature that mental anxiety has a close relationship with systolic blood pressure (SBP). As a biostatistician you want to compute this relationship and collected anxiety score and systolic blood pressure (SBP) from a random sample of 20 individuals. Here anxiety score is an independent variable (x) and SBP is a dependent variable mental anxiety (y). The following table shows the data.
Table: Anxiety score and systolic blood pressure
Individual idAnxiety score 0-100Systolic blood pressure 120-200 mmHg11012321312531512542512853513263913574014084514595515010651551165158127016013731601485165158517016881751790185189218519951902098195
1. From the above data set compute the correlation coefficient (r) (10 points)
Note: For using the formula of r, you need to calculate the covariance of (x, y), and variance of x and y.
2. Interpret the computed correlation coefficient (r) (5 points)
3. Compute the least square estimates of and (10 points)
Note: For calculation of and you need to calculate the mean and standard deviation (s) of x and y.
4. Interpret and (5 points)
Assignment 1:
It is evident from the medical literature that mental anxiety has a close relationship with systolic blood pressure (SBP). As a biostatistician you want to compute this relationship and collected anxiety score and systolic blood pressure (SBP) from a random sample of 20 individuals. Here anxiety score is an independent variable (x) and SBP is a dependent variable mental anxiety (y). The following table shows the data.
Table: Anxiety score and systolic blood pressure
|
Individual id |
Anxiety score 0-100 |
Systolic blood pressure 120-200 mmHg |
|
1 |
10 |
123 |
|
2 |
13 |
125 |
|
3 |
15 |
125 |
|
4 |
25 |
128 |
|
5 |
35 |
132 |
|
6 |
39 |
135 |
|
7 |
40 |
140 |
|
8 |
45 |
145 |
|
9 |
55 |
150 |
|
10 |
65 |
155 |
|
11 |
65 |
158 |
|
12 |
70 |
160 |
|
13 |
73 |
160 |
|
14 |
85 |
165 |
|
15 |
85 |
170 |
|
16 |
88 |
175 |
|
17 |
90 |
185 |
|
18 |
92 |
185 |
|
19 |
95 |
190 |
|
20 |
98 |
195 |
1. From the above data set compute the correlation coefficient (r) (10 points)
Note: For using the formula of r, you need to calculate the covariance of (x, y), and variance of x and y.
2. Interpret the computed correlation coefficient (r) (5 points)
3. Compute the least square estimates of and (10 points)
Note: For calculation of and you need to calculate the mean and standard deviation (s) of x and y.
4. Interpret and (5 points)
