CHECK: MCQ PART B CORRECT 100%
In a certain region of the country, the proportion of the population with blue eyes is
currently 17 percent. A random sample of 100 people will be selected from the
population. What is the mean of the sampling distribution of the sample proportion of
people with blue eyes for samples of size 100 ? - ANSWER0.17
At a national convention attended by many educators, about 30 percent of the
attendees are from the northeast. Of all the attendees of the national convention, 25 will
be selected at random to receive a free book. What are the mean and standard
deviation of the sampling distribution of the proportion of attendees from the northeast
for samples of size 25 ? - ANSWERC The mean is 0.3 and the standard deviation is
√0.3(0.7)/25.
A sample of manufactured items will be selected from a large population in which 8
percent of the items are defective. Of the following, which is the least value for a sample
size that will allow for the sampling distribution of the sample proportion to be assumed
approximately normal? - ANSWER125
According to a recent survey, 47.9 percent of housing units in a large city are rentals. A
sample of 210 housing units will be randomly selected. Which of the following must be
true for the sampling distribution of the sample proportion of housing units in the large
city that are rentals to be approximately normal? - ANSWERThe values of 210(0.479)
and 210(0.521) must be at least 10.
For two populations of rabbits, R and S, the proportions of rabbits with white markings
on their fur are given as pR and pS, respectively. Suppose that independent random
samples of 50 rabbits from R and 100 rabbits from S are selected. Let pˆR be the
sample proportion of rabbits with white markings from R, and let pˆS be the sample
proportion of rabbits with white markings from S. What is the standard deviation of the
sampling distribution of pˆR−pˆS ? - ANSWERD √pR(1−pR)50+pS(1−pS)100
A study reported that finger rings increase the growth of bacteria on health-care
workers' hands. Research suggests that 31 percent of health-care workers who wear
rings have bacteria on one or both hands, and 27 percent of health-care workers
without rings have bacteria on one or both hands. Suppose that independent random
samples of 100 health-care workers wearing rings and 100 health-care workers not
wearing rings are selected. What is the standard deviation of the sampling distribution of
the difference in the sample proportions (wear rings minus does not wear rings) of
health-care workers having bacteria on one or both hands? - ANSWERC
√0.31(0.69)100+0.27(0.73)100