Question
In: Statistics and Probability
The grade point averages for 11 randomly selected students are listed below. Assume the data are...
The grade point averages for 11 randomly selected students are listed below. Assume the data are normally distributed.
2.0 3.2 1.8 2.9 0.9 4.0 3.3 2.9 3.6 0.8 2.7
Construct a 99% confidence interval for the population standard deviation
Solutions
Expert Solution
From sample data,
= 2.55 , S = 1.0539
chi-square critical value at 0.01 significance level with 10 df = 2.156 , 25.188
99% confidence interval for 
is
Sqrt [ ( n - 1) S2 / 
U ] <
< Sqrt [ ( n - 1) S2 /
L]
sqrt [ 10 * 1.05392 / 25.188 ] <
< sqrt [ 10 * 1.05392 / 2.156 ]
0.664 <
< 2.211
99% CI is ( 0.664 , 2.211 )
orchestra answered 2 years agoRelated Solutions
The grade averages for 10 randomly selected junior college students are listed below. Assume the grade...
The grade averages for 10 randomly selected junior college
students are listed below. Assume the grade averages are normally
distributed. Find a 98% confidence interval for the true mean. 78
80 83 48 76 72 94 75 91 65
The grade point averages for 10 randomly selected students are listed below. Construct a 95% confidence...
The grade point averages for 10 randomly selected students are
listed below. Construct a 95% confidence interval for the
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2.3 4.0 3.1 1.8 3.3 2.5 0.5 3.8 2.3 2.7
The grade point averages (GPA) for 12 randomly selected college students are shown on the right....
The grade point averages (GPA) for 12 randomly selected college
students are shown on the right. Complete parts (a) through (c)
below. Assume the population is normally distributed.
2.2 3.4 2.9 1.8 0.8 4.0 2.4 1.3 3.9 0.5 2.4 3.3
(a) Find the sample mean.
x = _____ (Round to two decimal places as needed.)
(b) Find the sample standard deviation.
s= ______ (Round to two decimal places as needed.)
(c) Construct a 95% confidence interval for the...
The grade point averages (GPA) of 18 randomly selected college students are used to estimate the...
The grade point averages (GPA) of 18 randomly selected college
students are used to estimate the mean GPA of the college students.
The GPAs from the sample are as follows:
2.3 3.3 2.6 1.8
0.2
3.1 4.0 0.7
3.1
2.3 2.0 3.1 3.4 1.3 2.6 2.6
3.7 2.2
(5 points) Is it justified to use of the standard normal
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(10 points) If the population is assumed to be normally
distributed, construct a 98% confidence interval for the population
mean GPA. Show your work in...
Below are the grade point averages for 24 randomly chosen university business students during a recent...
Below are the grade point averages for 24 randomly chosen
university business students during a recent semester.
a) Is there sufficient evidence to indicate that the variances
for the four classifications of students are not the same? Assume
alpha is 0.05.
b) What is the p-value for this problem? Explain its meaning in
words.
c) Is there sufficient evidence to indicate that the means for
the four classifications of students are not the same? Use alpha =
0.05.
d) If...
Sample grade point averages for ten male students and ten female students are listed. Find the...
Sample grade point averages for ten male students and ten female
students are listed. Find the coefficient of variation for each of
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2.7 2.6 3.4 3.5 3.8 1.8 Females 2.7 3.9 2.2 3.8 3.5 4.1 2.1 3.8 3.9
2.5 The coefficient of variation for males is nothing%. (Round to
one decimal place as needed.)
Sample grade point averages for ten male students and ten female students are listed. Find the...
Sample grade point averages for ten male students and ten female
students are listed. Find the coefficient of variation for each of
the two data sets. Then compare the results
Males 2.5 3.8 3.6 3.9 2.6 2.6 3.6 3.2 3.9 1.8
Females 2.8 3.5 2.1 3.7 3.5 4.1 2.1 3.9 3.9 2.3
The coefficient of variation for males is __%.
The Coefficient of variation for females Is __ %
The following data are the monthly salaries y and the grade point averages x for students...
The following data are the monthly salaries y and the grade
point averages x for students who obtained a bachelor's degree in
business administration.
GPA
Monthly Salary ($)
2.7
3,600
3.5
3,800
3.6
4,200
3.2
3,700
3.4
4,200
2.8
2,400
The estimated regression equation for these data is y^ = -464.3
+ 1285.7x and MSE = 259,464
a. Develop a point estimate of the starting
salary for a student with a GPA of 3.0 (to 1 decimal).
b. Develop...
The following data are the monthly salaries y and the grade point averages x for students...
The following data are the monthly salaries y and the
grade point averages x for students who obtained a
bachelor's degree in business administration.
GPA
Monthly Salary ($)
2.6
3,600
3.5
3,800
3.6
4,300
3.2
3,700
3.5
4,100
2.8
2,400
The estimated regression equation for these data is =
40.7 + 1,127.9x and MSE =280,233.
a. Develop a point estimate of the starting
salary for a student with a GPA of 3.0 (to 1 decimal).
$
b. Develop a 95% confidence...
The following data are the monthly salaries y and the grade point averages x for students...
The following data are the monthly salaries y and the grade
point averages x for students who obtained a bachelor's degree in
business administration.
GPA
Monthly Salary ($)
2.6
3,600
3.4
3,800
3.6
4,300
3.2
3,700
3.4
4,100
3
2,400
The estimated regression equation for these data is y= 350 +
1031.3x and MSE = 383594.
Use Table 1 of Appendix B.
a. Develop a point estimate of the starting
salary for a student with a GPA of 3.0 (to...
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