An educator wanted to look at the study habits of university students. As part of the research, data was collected for three variables - the amount of time (in hours per week) spent studying, the amount of time (in hours per week) spent playing video games, and the GPA - for a sample of 20 male uni...
BUAL 2650 Final || with Error-free Solutions.
An educator wanted to look at the study habits of university students. As part of the research,
data was collected for three variables - the amount of time (in hours per week) spent studying,
the amount of time (in hours per week) spent playing video games, and the GPA - for a sample
of 20 male university students. As part of the research, a 95% confidence interval for the average
GPA of all male university students was calculated to be: (2.95, 3.10). Which of the following
statements is true? correct answers In construction of the confidence interval, a t-value with 19
degrees of freedom was used.
Private colleges and universities rely on money contributed by individuals and corporations for
their operating expenses. Much of this money is invested in a fund called an endowment, and the
college spends only the interest earned by the fund. A recent survey of eight private colleges in
the United States revealed the following endowments (in millions of dollars): 77.8, 45.1, 243.4,
489.5, 113.9, 187.6, 102.4, and 210.2. What value will be used as the point estimate for the mean
endowment of all private colleges in the United States? correct answers 183.738
Parking at a large university can be extremely difficult at times. One particular university is
trying to determine the location of a new parking garage. As part of their research, officials are
interested in estimating the average parking time of students from within the various colleges on
campus. Which of the following would represent the target parameter of interest? correct
answers mu (U)
What is Z a/2 when a=0.05? correct answers 1.96
A random sample of n measurements was selected from a population with unknown mean μ and
known standard deviation σ. Calculate a 95% confidence interval for μ for the given situation.
Round to the nearest hundredth when necessary.
n=100,x=74, o=25 correct answers 74 +/- 4.9
The registrar's office at State University would like to determine a 95% confidence interval for
the mean commute time of its students. A member of the staff randomly chooses a parking lot
and surveys the first 125 students who park in the chosen lot on a given day. The confidence
interval is correct answers not meaningful because of the lack of random sampling.
A random sample of 250 students at a university finds that these students take a mean of 14.3
credit hours per quarter with a standard deviation of 1.7 credit hours. The 95% confidence
interval for the mean is 14.3 ± 0.211. Interpret the interval. correct answers We are 95%
confident that the average number of credit hours per quarter of students at the university falls in
the interval 14.089 to 14.511 hours.
What type of car is more popular among college students, American or foreign? One hundred
fifty-nine college students were randomly sampled and each was asked which type of car he or
she prefers. A computer package was used to generate the printout below of a 95% confidence
interval for the proportion of college students who prefer American automobiles.
, SAMPLE PROPORTION = .396
SAMPLE SIZE = 159
UPPER LIMIT = .472
LOWER LIMIT = .320
Which of the following is a correct practical interpretation of the interval? correct answers We
are 95% confident that the proportion of all college students who prefer American cars falls
between .320 and .472.
A 90% confidence interval for the mean percentage of airline reservations being canceled on the
day of the flight is (1.1%, 3.2%). What is the point estimator of the mean percentage of
reservations that are canceled on the day of the flight? correct answers 2.15%
The director of a hospital wishes to estimate the mean number of people who are admitted to the
emergency room during a 24-hour period. The director randomly selects 49 different 24-hour
periods and determines the number of admissions for each. For this sample, x= 17.2 and s=5.
Estimate the mean number of admissions per 24-hour period with a 90% confidence interval.
correct answers 17.2 ± 1.198
Researchers have claimed that the average number of headaches per student during a semester of
Statistics is 11. Statistics students believe the average is higher. In a sample of n = 16 students,
the mean is 12 headaches with a deviation of 2.4. Which of the following represents the null and
alternative hypotheses necessary to test the students' belief? correct answers H0: μ = 11 vs. Ha: μ
> 11
The owner of Get-A-Away Travel has recently surveyed a random sample of 183 customers to
determine whether the mean age of the agency's customers is over 32. The appropriate
hypotheses are HO: μ =32, Ha: μ >32. If he concludes the mean age is over 32 when it is not, he
makes a ______ error. If he concludes the mean age is not over 32 when it is, he makes a ______
error. correct answers Type I; Type II
I want to test HO: p=.4 vs Ha p ≠ .4 using a test of hypothesis. If I concluded that p is .4 when, in
fact, the true value of p is not .4, then I have made a _________ correct answers Type II error
A consumer product magazine recently ran a story concerning the increasing prices of digital
cameras. The story stated that digital camera prices dipped a couple of years ago, but are now
beginning to increase in price because of added features. According to the story, the average
price of all digital cameras a couple of years ago was $215.00. A random sample of cameras was
recently taken and entered into a spreadsheet. It was desired to test to determine if that average
price of all digital cameras is now more than $215.00. What null and alternative hypothesis
should be tested? correct answers H0: μ = 215 vs. HA: μ > 215
A consumer product magazine recently ran a story concerning the increasing prices of digital
cameras. The story stated that digital camera prices dipped a couple of years ago, but now are
beginning to increase in price because of added features. According to the story, the average
price of all digital cameras a couple of years ago was $215.00. A random sample of cameras was
recently taken and entered into a spreadsheet. It was desired to test to determine if that average
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