EXAM 3 SET BUSINESS STATS
QUESTIONS WITH ACCURATE
ANSWERS
___________
⎷p(1-p)/n correct answer That is, if the population is finite with n/N ≤ .05, we will
use ________________.
- theorem applies additional information to revise probabilities correct answer
Bayes'
(T/F) The means (x-bar s) of 98% of samples will always be within the confidence
interval [x-bar-2.33(s/√N)]<u<[x-bar + 2.33(s/√N)] correct answer False
(T/F) The means x-bar s of 98% of samples will always be within the probability
interval [u-2.33(s/√N)] to [u+2.33(s/√N)] correct answer True
15 accounting majors had an average grade of 90 on a finance exam. Seven
marketing majors averaged 85, while ten finance majors averaged 93 on the same
exam. What is the weighted mean for the 32 students taking the exam? correct
answer 89.84
30 correct answer General statistical practice is to assume that, for most
applications, the sampling distribution of x can
̄ be approximated by a normal
distribution whenever the sample is size ____or more.
,50 correct answer In cases where the population is highly skewed or outliers are
present, samples of size ____ may be needed.
80% of the trainees are female, 20% male.
90% of the females attended college, 78% of the males attended college. A
management trainee is selected at random. What is the probability that the
person selected is a female who did NOT attend college? correct answer 0.08
A - chart is useful for displaying the relative frequency distribution for a nominal
variable correct answer Pie or Bar
A 95% confidence interval for a population mean is determined to be 100 to 120.
If the confidence coefficient is reduced to 0.90, the interval for μ correct answer
becomes narrower
A 95% confidence interval for mu can be interpreted to mean that if we take 100
samples of the same size and construct 100 such confidence intervals for mu then
correct answer 95 of the intervals are expected to include u
A board of directors consists of 8 men and 4 women. A 4-member search
committee is randomly chosen to recommend a new company president. What is
the probability that all 4 members of the search committee will be women?
correct answer 1/495 or 0.002
A frequency polygon is a very useful graphic technique when correct answer
Comparing two or more distributions.
,A group of 100 students were surveyed about their interest in a new Economics
major. Interest was measured in terms of high, medium, or low.What is the best
way to illustrate the relative frequency of student interest? correct answer A pie
chart
A group of statistics students conducts a survey at their university to find the
mean amount of time students study per week. Based on a simple random
sample, they surveyed 144 students. The statistics showed that students studied
an average of 20 hours per week with a standard deviation of 10 hours. What is
the probability of finding a sample mean less than 18 hours? correct answer
0.0082
A light bulb has an average service life of 750 hours, with a standard deviation of
50. If the service life of the light bulbs approximates a normal distribution, about
what percent of the distribution will be between 600 and 900 hours? correct
answer 99.7%
A new computer game has been developed and 80 veteran game players will test
its market potential. If 60 players liked the game, what is the probability that any
veteran game player will like the new computer game? correct answer 0.75
A new manufacturing process is implemented. The quality control division has no
historic estimate for p. How large a sample should be taken to be 95% confident
that the sample proportion is within .02 of the population proportion? correct
answer 2401
A pie chart is similar to correct answer A relative frequency distribution
A pie chart shows the correct answer Relative frequencies of a qualitative variable
, A point estimate is a single value used to estimate a correct answer Population
parameter
A population is a collection of correct answer All individuals, objects, or
measurements of interest
A probability distribution correct answer A mutually exclusive and collectively
exhaustive listing of experimental outcomes that can occur by chance and their
corresponding probabilities
A random sample of 42 college graduates revealed that they worked an average
of 5.5 years on the job before being promoted. The population standard deviation
was 1.1 years. Using the 0.99 degree of confidence, what is the confidence
interval for the population mean? correct answer 5.06 and 5.94
A random sample of 85 group leaders and supervisors revealed that they worked
an average of 6.5 years before being promoted. The population standard
deviation was 1.7 years. Using the 0.95 degree of confidence, what is the
confidence interval for the population mean? correct answer 6.14 and 6.86
A random variable represents the outcomes of correct answer An experiment
A researcher wants to make a 95% confidence interval for the population mean.
She wants the maximum error of estimate to be within 2.5 of the population
mean. The population standard deviation is known to be 10.5o. The sample size
that will yield a maximum error of estimate within 2.5 of the population mean is:
correct answer 68
QUESTIONS WITH ACCURATE
ANSWERS
___________
⎷p(1-p)/n correct answer That is, if the population is finite with n/N ≤ .05, we will
use ________________.
- theorem applies additional information to revise probabilities correct answer
Bayes'
(T/F) The means (x-bar s) of 98% of samples will always be within the confidence
interval [x-bar-2.33(s/√N)]<u<[x-bar + 2.33(s/√N)] correct answer False
(T/F) The means x-bar s of 98% of samples will always be within the probability
interval [u-2.33(s/√N)] to [u+2.33(s/√N)] correct answer True
15 accounting majors had an average grade of 90 on a finance exam. Seven
marketing majors averaged 85, while ten finance majors averaged 93 on the same
exam. What is the weighted mean for the 32 students taking the exam? correct
answer 89.84
30 correct answer General statistical practice is to assume that, for most
applications, the sampling distribution of x can
̄ be approximated by a normal
distribution whenever the sample is size ____or more.
,50 correct answer In cases where the population is highly skewed or outliers are
present, samples of size ____ may be needed.
80% of the trainees are female, 20% male.
90% of the females attended college, 78% of the males attended college. A
management trainee is selected at random. What is the probability that the
person selected is a female who did NOT attend college? correct answer 0.08
A - chart is useful for displaying the relative frequency distribution for a nominal
variable correct answer Pie or Bar
A 95% confidence interval for a population mean is determined to be 100 to 120.
If the confidence coefficient is reduced to 0.90, the interval for μ correct answer
becomes narrower
A 95% confidence interval for mu can be interpreted to mean that if we take 100
samples of the same size and construct 100 such confidence intervals for mu then
correct answer 95 of the intervals are expected to include u
A board of directors consists of 8 men and 4 women. A 4-member search
committee is randomly chosen to recommend a new company president. What is
the probability that all 4 members of the search committee will be women?
correct answer 1/495 or 0.002
A frequency polygon is a very useful graphic technique when correct answer
Comparing two or more distributions.
,A group of 100 students were surveyed about their interest in a new Economics
major. Interest was measured in terms of high, medium, or low.What is the best
way to illustrate the relative frequency of student interest? correct answer A pie
chart
A group of statistics students conducts a survey at their university to find the
mean amount of time students study per week. Based on a simple random
sample, they surveyed 144 students. The statistics showed that students studied
an average of 20 hours per week with a standard deviation of 10 hours. What is
the probability of finding a sample mean less than 18 hours? correct answer
0.0082
A light bulb has an average service life of 750 hours, with a standard deviation of
50. If the service life of the light bulbs approximates a normal distribution, about
what percent of the distribution will be between 600 and 900 hours? correct
answer 99.7%
A new computer game has been developed and 80 veteran game players will test
its market potential. If 60 players liked the game, what is the probability that any
veteran game player will like the new computer game? correct answer 0.75
A new manufacturing process is implemented. The quality control division has no
historic estimate for p. How large a sample should be taken to be 95% confident
that the sample proportion is within .02 of the population proportion? correct
answer 2401
A pie chart is similar to correct answer A relative frequency distribution
A pie chart shows the correct answer Relative frequencies of a qualitative variable
, A point estimate is a single value used to estimate a correct answer Population
parameter
A population is a collection of correct answer All individuals, objects, or
measurements of interest
A probability distribution correct answer A mutually exclusive and collectively
exhaustive listing of experimental outcomes that can occur by chance and their
corresponding probabilities
A random sample of 42 college graduates revealed that they worked an average
of 5.5 years on the job before being promoted. The population standard deviation
was 1.1 years. Using the 0.99 degree of confidence, what is the confidence
interval for the population mean? correct answer 5.06 and 5.94
A random sample of 85 group leaders and supervisors revealed that they worked
an average of 6.5 years before being promoted. The population standard
deviation was 1.7 years. Using the 0.95 degree of confidence, what is the
confidence interval for the population mean? correct answer 6.14 and 6.86
A random variable represents the outcomes of correct answer An experiment
A researcher wants to make a 95% confidence interval for the population mean.
She wants the maximum error of estimate to be within 2.5 of the population
mean. The population standard deviation is known to be 10.5o. The sample size
that will yield a maximum error of estimate within 2.5 of the population mean is:
correct answer 68
