Question 1
3.33 / 3.33 pts
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Allante Pizza delivers pizzas throughout its local market area at
no charge to the customer. However, customers often tip the
driver. The owner is interested in estimating the mean tip
income per delivery. To do this, she has selected a simple
random sample of 12 deliveries and has recorded the tips that
were received by the drivers. These data are:
$2.25
$2.50
$2.25
$2.00
$2.00
$1.50
$0.00
$2.00
$1.50
$2.00
$3.00
$1.50
Suppose the owner is interested in developing a 90% confidence
interval estimate. Given the fact that the population standard
deviation is unknown, what distribution will be used to obtain
the critical value?
z

distribution
Correct!
t

distribution
k

distribution
s

distribution
Question 2
3.33 / 3.33 pts
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Suppose a study of 196 randomly sampled privately insured
adults with incomes over 200% of the current poverty level is to
be used to measure out

of

pocket medical expenses for
prescription drugs for this income class. The sample data are in
the file
Drug Expenses
.
Based on the sample data, construct a 95% confidence interval
estimate for the mean annual out

of

pocket expenditures on
prescription drugs for this income class. Interpret this interval.
(161.97, 173.07)
(162.08, 172.96)
Correct!
(163.50, 171.54)
(164.19, 170.85)
Question 3
3.33 / 3.33 pts
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A pilot sample of 75 items was taken, and the number of items
with the attribute of interest was found to be 15. How many more items must be sampled to construct a 99% confidence interval estimate for pwith a 0.025 margin of error?