Assignment title: Information
Economics
Q
Question 1 (22 marks)
The data set Library2012New.sav, available on the course StudyDesk, contains infor-
mation on several variables of some selected libraries including city, accreditation, year
of establishment, total revenue, operational revenue, number of books and registered
borrowers. Here we are interested in the accreditation status and handicapped access
facility.
(a) Produce a two-way (contingency) table to investigate any association betw
een ac-
creditation status and handicapped access facility. [4 marks]
STA2300—Data Analysis 5
(b) Find the joint distribution of accreditation status and handicapped access facility.
[4 marks]
(c) In no more than 60 words, describe any special features (variation in the cell, and/or,
row/column percentages) of the joint distribution. [3 marks]
(d) Find the (conditional) distribution of handicapped access facility for non-accredited
libraries. [4 marks]
(e) What percentages of accredited libraries have a handicapped access facility? [3
Marks]
(f) Is there any indication of an association (relationship) between accreditation status
and handicapped access facility? Support your answer by any evidence from the
data. [4 marks]
Question 2 (20 marks)
The data set Library2012New.sav, available on the course StudyDesk, contains infor-
mation on several variables of some selected libraries including city, accreditation, year
of establishment, total revenue, operational revenue, number of books and registered
borrowers. Here we are interested to investigate the association between the number of
registered borrowers and number of children's materials in circulation.
(a) Use an appropriate graph to display the relationship between the number of regis-
tered borrowers and number of children's materials in circulation. [6 marks]
(b) Describe the form, direction and strength of the relationship between the number
of registered borrowers and number of children's materials in circulation in about
40 words. [4 marks]
(c) Calculate the value of an appropriate statistic to describe the strength of the linear
association between the number of registered borrowers and number of children's
materials in circulation. [2 marks]
(d) Write the equation of the regression line to predict the value of the number of
children's materials in circulation based on the number of registered borrowers. [4
marks]
(e) Use the above regression equation to predict the number of children's materials in
circulation for the library having 56425 registered borrowers. [Refer to case 85 of
the data set.] [2 marks]
(f) From the above predicted number of children's materials in circulation, find the
residual if the observed number in circulation is 182571. [2 marks]
STA2300—Data Analysis 6
Question 3 (16 marks)
The data set Library2012New.sav, available on the course StudyDesk, contains infor-
mation on several variables of some selected libraries including city, accreditation, year
of establishment, total revenue, operational revenue, number of books and registered
borrowers. Here we are interested to investigate the distribution of hours open per week.
(a) Use an appropriate graph to display the distribution of the hours open per week. [4
marks]
(b) Describe the shape, centre and spread of the distribution in about 50 words. [4
marks]
(c) On the same graph, display the two distributions of the hours open per week for the
accredited and non-accredited libraries. [4 marks]
(d) Compare the two distributions of the hours open per week for the accredited and
non-accredited libraries in no more than 60 words. [4 marks]
Question 4 (16 marks)
A recent business survey in Toowoomba reveals that 20% of the retail shops plan to hire
new staff within the Financial year. An Economics professor at USQ takes a random
sample of 15 retail shops in Toowoomba to study the issue more thoroughly. A particular
variable of interest is the number of retail shops planning to hire new staff. Based on
the above information answer the following questions:
(a) What is an appropriate model to represent the variable of interest? Write down the
parameters of the model, if any. [3 marks]
(b) Discuss how the conditions of the above model are satisfied in the current study. [4
marks]
(c) Find the mean and standard deviation of the model using the parameters of the
model. [3 marks]
(d) What is the probability that at least 2 of the retail shops in the sample plan to hire
new staff? [3 marks]
(e) What is the probability that no more than 2 of the retail shops in the sample plan
STA2300—Data Analysis 7
Question 5 (14 marks)
How does a new vaccine protect from the Swine Flu? A pharmaceutical company
prepared three levels of doses for a new Flu vaccine to be tested clinically. The first level
A contained 5ml, the second level B contained 7.5ml, and the third level C contained
10ml of the actual drug. The vaccine was administered to a group of 150 randomly
selected healthy adults equally divided for the three levels of doses. Another 50 randomly
selected healthy adults received a placebo. Like the health workers who administered
the vaccine, the subjects were not aware of the level of dose or placebo they received.
The incidence of Swine Flu was monitored for a period of six months, and the data were
recorded for each group of subjects.
(a) For the above study identify, if appropriate,
(i) the response variable(s). [2 marks]
(ii) the factor and its levels. [2 marks]
(iii) the experimental units. [1 mark]
(b) Is this an experimental or observational study? Justify your answer in the context
of the question. [2 marks]
(c) Is this a double blinded study? Explain it in the context of this study. [2 marks]
(d) What was the sample size for the study? [1 mark]
(e) Are the four principles of experimental design used in this study? Explain, in the
context of the study. [4 marks]
Question 6 (12 marks)
The height of the members of a city basketball club is distributed according to a normal
model with mean _ = 170cm and standard deviation _ = 6cm.
(a) What is the probability that a randomly selected member of the club is taller than
160cm? [2 marks]
(b) What proportion of the members are of height between 164cm and 182cm? [3 marks]
(c) Suppose that the tallest 10% of the members are selected for a friendly weekend
match. What is the minimum height to be selected for the match? [3 marks]
STA2300—Data Analysis 8
(d) What is the cutoff height for the shortest 28.1% of the members of the club? [4
marks]