In: Statistics and Probability
A study was done on body temperatures of men and women. The results are shown in the table. Assume that the two samples are independent simple random samples selected from normally distributed populations, and do not assume that the population standard deviations are equal. Complete parts (a) and (b) below. Use a 0.01 significance level for both parts. |
Men |
Women |
|||
---|---|---|---|---|---|
muμ |
μ1 |
μ2 |
|||
n |
11 |
59 |
|||
x overbarx |
97.59 °F |
97.36 °F |
|||
s |
0.96 °F |
0.72 °F |
a. Test the claim that men have a higher mean body temperature than women.
What are the null and alternative hypotheses?
A. H0: μ1 ≠ μ2
H1: μ1 < μ2
B. H0: μ1 = μ2
H1: μ1 ≠ μ2
C. H0: μ1 = μ2
H1: μ1 > μ2
D. H0: μ1g ≥ μ2
H1: μ1 < μ2
The test statistic, t, is ??? (Round to two decimal places as needed.)
The P-value is ??? (Round to three decimal places as needed.)
State the conclusion for the test.
A. Fail to rejectFail to reject the null hypothesis. There is sufficient evidence to support the claim that men have a higher mean body temperature than women.
B. Fail to rejectFail to reject the null hypothesis. There is notis not sufficient evidence to support the claim that men have a higher mean body temperature than women.
C. Reject the null hypothesis. There is sufficient evidence to support the claim that men have a higher mean body temperature than women.
D. Reject the null hypothesis. There is notis not sufficient evidence to support the claim that men have a higher mean body temperature than women.
b. Construct a confidence interval suitable for testing the claim that men have a higher mean body temperature than women.
???<mμ1−μ2<???
(Round to three decimal places as needed.)
Does the confidence interval support the conclusion found with the hypothesis test?
▼??(Yes, No,) because the confidence interval contains ▼(zero., only negative values.,only positive values.)
2.
Listed below are systolic blood pressure measurements (mm Hg) taken from the right and left arms of the same woman. Assume that the paired sample data is a simple random sample and that the differences have a distribution that is approximately normal. Use a 0.01significance level to test for a difference between the measurements from the two arms. What can be concluded?
Right arm |
147 |
136 |
141 |
133 |
132 |
|
---|---|---|---|---|---|---|
Left arm |
172 |
168 |
191 |
155 |
151 |
In this example, μd is the mean value of the differences d for the population of all pairs of data, where each individual difference d is defined as the measurement from the right arm minus the measurement from the left arm. What are the null and alternative hypotheses for the hypothesis test?
Listed below are systolic blood pressure measurements (mm Hg) taken from the right and left arms of the same woman. Assume that the paired sample data is a simple random sample and that the differences have a distribution that is approximately normal. Use a
0.010.01
significance level to test for a difference between the measurements from the two arms. What can be concluded?
Right arm |
147147 |
136136 |
141141 |
133133 |
132132 |
|
---|---|---|---|---|---|---|
Left arm |
172172 |
168168 |
191191 |
155155 |
151151 |
In this example,
mu Subscript dμd
is the mean value of the differences d for the population of all pairs of data, where each individual difference d is defined as the measurement from the right arm minus the measurement from the left arm. What are the null and alternative hypotheses for the hypothesis test?
Listed below are systolic blood pressure measurements (mm Hg) taken from the right and left arms of the same woman. Assume that the paired sample data is a simple random sample and that the differences have a distribution that is approximately normal. Use a
0.010.01
significance level to test for a difference between the measurements from the two arms. What can be concluded?
Right arm |
147147 |
136136 |
141141 |
133133 |
132132 |
|
---|---|---|---|---|---|---|
Left arm |
172172 |
168168 |
191191 |
155155 |
151151 |
In this example,
mu Subscript dμd
is the mean value of the differences d for the population of all pairs of data, where each individual difference d is defined as the measurement from the right arm minus the measurement from the left arm. What are the null and alternative hypotheses for the hypothesis test?
A. H0: μd ≠ 0
H1: μd > 0
B. H0: μd = 0
H1: μd < 0
C.H0:μd = 0
H1: dμ ≠ 0
D. H0:μd ≠ 0
H1:μd = 0
Identify the test statistic.
t = ??? (Round to two decimal places as needed.)
Identify the P-value.
P-value =??? (Round to three decimal places as needed.)
What is the conclusion based on the hypothesis test?
Since the P-value is ▼(less, greater) than the significance level, ▼(fail to reject, reject) the null hypothesis. There ▼(is not, is) sufficient evidence to support the claim of a difference in measurements between the two arms.
1 HYpothesis Testing
The test hypothesis is
This is a one-sided test because the alternative hypothesis is
formulated to detect the difference from the hypothesized mean on
the upper side
Now, the value of test static can be found out by following
formula:
.
Degrees of freedom on the t-test statistic are n1 + n2 - 2 = 11
+ 59 - 2 = 68
This implies that
OPTION B
Fail to reject the null hypothesis. There is notis not sufficient
evidence to support the claim that men have a higher mean body
temperature than women.
CONFIDENCE INTERVAL
Confidence interval(in %) = 99
Given, POpulation variances are not equal
First we calculate degree of freedom
Required confidence interval = (0.23 - 0.763, 0.23 + 0.763)
Required confidence interval = (-0.533, 0.993)
YES
the confidence interval support the conclusion found with the
hypothesis test because the confidence interval contains ZERO