QNT 561 FINAL EXAM Q&A A market researcher is interested in determining the average income for families
in San Mateo County, California. To
... [Show More] accomplish this, she takes a random sample
of 300 families from the county and uses the data gathered from them to
estimate the average income for families of the entire county. This process is an
example of
o Inferential statistics
If x is a binomial random variable with n=10 and p=0.8, what is the probability
that x is equal to 4?
o .0055
The number of bags arriving on the baggage claim conveyor belt in a 3 minute
time period would best be modeled with the _________.
o Poisson distribution
According to the central limit theorem, for samples of size 64 drawn from a
population with μ = 800 and σ = 56, the standard deviation of the sampling
distribution of sample means would equal _______.
o 7
Suppose a population has a mean of 400 and a standard deviation of 24. If a
random sample of size 144 is drawn from the population, the probability of
drawing a sample with a mean less than 402 is _______.
o 0.8413
If x is a binomial random variable with n=10 and p=0.8, the mean value of x is
_____.
o 8
According to the central limit theorem, for samples of size 64 drawn from a
population with μ = 800 and σ = 56, the mean of the sampling distribution of
sample means would equal _______.
o 800
Completion time (from start to finish) of a building remodeling project is
normally distributed with a mean of 200 work-days and a standard deviation of
10 work-days. To be 99% sure that we will not be late in completing the project,
we should request a completion time of _______ work-days.
o 223
A researcher wants to determine the sample size necessary to adequately
conduct a study to estimate the population mean to within 5 points. The
standard deviation of population values is 80 and the researcher plans to use a
90% level of confidence. The sample size should be at least _______.
o 44
The expected (mean) life of a particular type of light bulb is 1,000 hours with a
standard deviation of 50 hours. The life of this bulb is normally
distributed. What is the probability that a randomly selected bulb would last
fewer than 940 hours?
o 0.1151
A large national company is considering negotiating cellular phone rates for its
employees. The Human Resource department would like to estimate the
proportion of its employee population who own an Apple iPhone. A random
sample of size 250 is taken and 40% of the sample own and iPhone. The 95%
confidence interval to estimate the population proportion is _______.
o 0.34 to 0.46 [Show Less]