Question
The researchers suggest that there are occupational differences in mean testosterone level. Medical doctors and university...
The researchers suggest that there are occupational differences in mean testosterone level. Medical doctors and university professors are two of the occupational groups for which means and standard deviations are recorded and listed in the following table.
| Group | Sample size | Mean | StDev |
|---|---|---|---|
| MD | n1 = 8 | [(x)]1 = 10.43 | s1 = 2.99 |
| Prof | n2 = 11 | [(x)]2 = 10.56 | s2 = 3.95 |
Let us denote:
- μ1: population mean testosterone among medical doctors,
- μ2: population mean testosterone among university professors,
- σ1: population standard deviation of testosterone among medical doctors,
- σ2: population standard deviation of testosterone among university professors.
Case 1: Assume that the population standard deviations
are unequal, i.e. σ1 ≠ σ2.
What is the standard error of the difference in sample mean
[(x)]1 − [(x)]2? i.e.
s.e.([(x)]1−[(x)]2)
= [answer to 4 decimal places]
| Tries 0/5 |
Which of the following options gives the formula for 90%
confidence interval for μ1−μ2?
−0.13 ±2.9
×s.e.([(x)]1−[(x)]2)
−0.13 ±1.74
×s.e.([(x)]1−[(x)]2)
−0.13 ±2.57
×s.e.([(x)]1−[(x)]2)
−0.13 ±2.11
×s.e.([(x)]1−[(x)]2)
−0.13 ±1.33
×s.e.([(x)]1−[(x)]2)
| Tries 0/3 |
Are there significant difference between mean testosterone
levels of medical doctors and university professors?
no, because [(x)]1 =
[(x)]2
yes, because the entire 90% confidence interval for
μ1−μ2 does not contain 0
no, because the 90% confidence interval for
μ1−μ2 contains 0
yes, because [(x)]1 ≠
[(x)]2
| Tries 0/3 |
Case 2: Now assume that the population standard
deviations are equal, i.e. σ1 =
σ2.
Compute the pooled standard deviation,
spooled [answer to 4 decimal
places]
| Tries 0/5 |
Which of the following options gives the formula for 90%
confidence interval for μ1−μ2 for pooled
situation?
−0.13 ±2.57 ×1.6663
−0.13 ±2.11 ×1.6663
−0.13 ±2.9 ×1.6663
−0.13 ±1.33 ×1.6663
−0.13 ±1.74 ×1.6663
| Tries 0/3 |
What is the margin of error of the 90% pooled confidence interval of μ1−μ2? [answer to 4 decimal places]
Homework Answers
Answer #1
Not the answer you're looking for?
Similar Questions
The researchers suggest that there are occupational differences in mean testosterone level. Medical doctors and university...
The researchers suggest that there are occupational differences
in mean testosterone level. Medical doctors and university
professors are two of the occupational groups for which means and
standard deviations are recorded and listed in the following
table.
Group
Sample size
Mean
StDev
MD
n1=6n1=6
x¯1=11.21x¯1=11.21
s1=3.73s1=3.73
Prof
n2=5n2=5
x¯2=11.6x¯2=11.6
s2=2.14s2=2.14
Let us denote:
μ1:μ1: population mean testosterone among medical doctors,
μ2:μ2: population mean testosterone among university
professors,
σ1:σ1: population standard deviation of testosterone among
medical doctors,
σ2:σ2: population standard deviation...
The researchers suggest that there are occupational differences in mean testosterone level. Medical doctors and university...
The researchers suggest that there are occupational differences
in mean testosterone level. Medical doctors and university
professors are two of the occupational groups for which means and
standard deviations are recorded and listed in the following
table.
Group
Sample size
Mean
StDev
MD
n1=4n1=4
x¯1=11.17x¯1=11.17
s1=2.07s1=2.07
Prof
n2=3n2=3
x¯2=10.11x¯2=10.11
s2=2.83s2=2.83
Let us denote:
μ1:μ1: population mean testosterone among medical doctors,
μ2:μ2: population mean testosterone among university
professors,
σ1:σ1: population standard deviation of testosterone among
medical doctors,
σ2:σ2: population standard deviation...
The researchers suggest that there are occupational differences in mean testosterone level. Medical doctors and university...
The researchers suggest that there are occupational differences
in mean testosterone level. Medical doctors and university
professors are two of the occupational groups for which means and
standard deviations are recorded and listed in the following
table.Let us denote:
?1: population mean testosterone among medical doctors,
?2: population mean testosterone among university
professors,
?1: population standard deviation of testosterone among medical
doctors,
?2: population standard deviation of testosterone among
university professors.
Group
Sample size
Mean
StDev
MD
n1 = 6...
The owner of two stores tracks the times for customer service in seconds. She thinks store...
The owner of two stores tracks the times for customer service in
seconds. She thinks store 1 has longer service times. Perform a
hypothesis test on the difference of the means. We know the
population standard deviations. (This is rare.)
Population 1 has standard deviation σ1=σ1= 4.5
Population 2 has standard deviation σ2=σ2= 4.5
The populations are normal. Use alph=0.05alph=0.05
Use the claim for the alternate hypothesis.
Service time store 1
174
184
170
174
174
189
174
179
176...
A random sample of n1 = 14 winter days in Denver gave a sample mean pollution...
A random sample of n1 = 14 winter days in
Denver gave a sample mean pollution index x1 =
43. Previous studies show that σ1 = 21. For
Englewood (a suburb of Denver), a random sample of
n2 = 12 winter days gave a sample mean
pollution index of x2 = 37. Previous studies
show that σ2 = 17. Assume the pollution index
is normally distributed in both Englewood and Denver.
(a) Do these data indicate that the mean population...
Researchers at P University and W State University found that airlines are doing a better job...
Researchers at P University and W State University found that
airlines are doing a better job of getting passengers to their
destinations on time.† AirTran Airways and Southwest Airlines were
among the leaders in on-time arrivals with both having 88% of their
flights arriving on time. But for the 12% of flights that were
delayed, how many minutes were these flights late? Sample data
showing the number of minutes that delayed flights were late are
provided in the file named...
Consider the following data drawn independently from normally distributed populations: (You may find it useful to...
Consider the following data drawn independently from normally
distributed populations: (You may find it useful to
reference the appropriate table: z table
or t table)
x−1x−1 = 34.4
x−2x−2 = 26.4
σ12 = 89.5
σ22 = 95.8
n1 = 21
n2 = 23
a. Construct the 90% confidence interval for the
difference between the population means.
(Negative values should be indicated by a
minus sign. Round all intermediate calculations to at least 4
decimal places and final answers to 2...
1. In the study examining socioeconomic differences in birth weight, the mean birth weight for babies...
1. In the study examining socioeconomic differences in birth
weight, the mean birth weight for babies born to n1=32
mothers with a college education was 2998 grams with a standard
deviation of 230 grams, while the mean birth weight for babies born
to n2=41 mothers with no more than a high school
education was 2765 grams with a standard deviation of 332 grams.
Which of the following states the appropriate hypotheses for
testing if the mean birth weight between these...
You are conducting an experiment in which you measure two means. Your null hypothesis is that...
You are conducting an experiment in which you measure two means.
Your null hypothesis is that they are the same (i.e. μ1 - μ2 = 0)
and your experiment will test this hypothesis with a confidence
level of alpha = 0.05. You would like to be able to detect a
difference in means of+/- 1 with a probability of at least 0.9. How
many samples do you need to test? The standard deviations of the
two groups are σ1 =...
Consider the following data drawn independently from normally distributed populations: x1 = 34.4 x2 = 26.4...
Consider the following data drawn independently from normally
distributed populations:
x1 = 34.4
x2 = 26.4
σ12 = 89.5
σ22 = 95.8
n1 = 21
n2 = 23
a. Construct the 90% confidence interval for the
difference between the population means.
(Negative values should be indicated by a
minus sign. Round all intermediate calculations to at least 4
decimal places and final answers to 2 decimal
places.)
Confidence interval is__________ to__________.
b. Specify the competing hypotheses in order to
determine...
ADVERTISEMENT
Need Online Homework Help?
Get Answers For Free
Most questions answered within 1 hours.
ADVERTISEMENT
Active Questions
asked 2 minutes ago
asked 2 minutes ago
asked 30 minutes ago
asked 42 minutes ago
asked 43 minutes ago
asked 1 hour ago
asked 1 hour ago
asked 1 hour ago
asked 1 hour ago
asked 1 hour ago
asked 1 hour ago
asked 1 hour ago