The average daily sodium intake X) and the average systolic
blood pressure (Y) of 25 patients...
The average daily sodium intake X) and the average systolic
blood pressure (Y) of 25 patients with high blood pressure found a
sample (Pearson product moment) correlation of 0.82. Assuming X and
Y have a bivariate normal distribution.
(a) Give a 95% confidence interval for the population
correlation coefficient.
(b) Test the hypothesis that X and Y are independent at level
0.05 using a large sample Z test statistic. Give the
p-Value.
(c) Redo (b) use your answer in (a)
You can use R to solve it if it is easier
Solutions
Expert Solution
a. CI
b. Hypothesis
c. We
see that confidence interval is ( 0.6285,0.9178) which
does not include zero. Hence we reject the null hypothesis and
conclude that the correlation coefficient is significant.
1. The following table gives the systolic blood pressure and age
of patients.
Systolic Blood Pressure
Age
131
34
132
36
122
30
119
32
123
26
115
23
137
37
a) Determine an r value for this data and classify the value as
weak, moderate, or strong.
b) Based on your calculated r value, what can you say about the
slope of the regression line?
c) Determine the model equation. This is also called the
regression line or the...
Below are the ages of six patients with blood pressure
problems.
Age, x
Blood Pressure, y
43
128
48
120
56
135
61
143
67
141
70
152
Use this data to determine if there is a correlation between the
age and blood pressure using the significance level of
α=0.05.
What is the p-value?
The table gives systolic blood pressure readings for Intensive
Care Unit patients in their teens and those in their eighties.
Teen
100
100
104
104
112
130
130
136
140
140
142
146
156
Eighties
80
100
100
110
110
122
130
135
136
138
140
141
162
190
190
A) Plot systolic blood pressure side-by-side boxplot for teen
and eighties, compare the spread of systolic blood pressure for
each group.
Q1
Q3
Teen
104
140
Eighties
110
140.5
B)...
Systolic blood pressure is the amount of pressure that blood
exerts on blood vessels while the heart is beating. The mean
systolic blood pressure for people in the United States is reported
to be 122 millimeters of mercury (mmHg) with a standard deviation
of 15 mmHg.
The wellness department of a large corporation is investigating
whether the mean systolic blood pressure of its employees is
greater than the reported national mean. A random sample of 50
employees will be selected,...
A pharmaceutical company claims that its new drug reduces
systolic blood pressure. The systolic blood pressure (in
millimeters of mercury) for nine patients before taking the new
drug and 2 hours after taking the drug are shown in the table
below. Is there enough evidence to support the company's claim? Let
d = (blood pressure before taking new drug) − (blood pressure after
taking new drug). Use a significance level of α = 0.05 for the
test. Assume that the...
A pharmaceutical company claims that its new drug reduces
systolic blood pressure. The systolic blood pressure (in
millimeters of mercury) for nine patients before taking the new
drug and 2 hours after taking the drug are shown in the table
below. Using this data, find the 99% confidence interval for the
true difference in blood pressure for each patient after taking the
new drug. Assume that the blood pressures are normally distributed
for the population of patients both before and...
A pharmaceutical company claims that its new drug reduces
systolic blood pressure. The systolic blood pressure (in
millimeters of mercury) for nine patients before taking the new
drug and 2 hours after taking the drug are shown in the table
below. Using this data, find the 99% confidence interval for the
true difference in blood pressure for each patient after taking the
new drug. Assume that the blood pressures are normally distributed
for the population of patients both before and...
A pharmaceutical company claims that its new drug reduces
systolic blood pressure. The systolic blood pressure (in
millimeters of mercury) for nine patients before taking the new
drug and 22 hours after taking the drug are shown in the table
below. Is there enough evidence to support the company's claim?
Let d=(blood pressure before taking new drug)−(blood pressure
after taking new drug). Use a significance level of α=0.01 for the
test. Assume that the systolic blood pressure levels are normally...
A pharmaceutical company claims that its new drug reduces
systolic blood pressure. The systolic blood pressure (in
millimeters of mercury) for nine patients before taking the new
drug and 2 hours after taking the drug are shown in the table
below. Is there enough evidence to support the company's claim?
Let d=(blood pressure before taking new drug)−(blood pressure
after taking new drug). Use a significance level of α=0.01 for the
test. Assume that the systolic blood pressure levels are normally...