devils are endangered due to a contagious facial tumour disease that threatens
the survival of the species. A recent survey in the Cradle Mountain region of
Tasmania located 136 Tasmanian Devils.
Forty-nine of these animals were not diseased and eighty-seven had contracted
the disease. Questions 1 and 2 are based on these data. Information relating to each of the Tasmanian
devils was recorded as follows:
Sex sex of Tasmanian
Devil: 1 = male, 2 = female
Age age of Tasmanian
Devil: 1 = young, 2 = adult,
3 = elderly
Diseased whether Devil was
diseased or not: 0 = diseased, 1 = not diseased
Length total length from
tip of nose to tip of tail in cm
Weight weight in kg
Headlength length of head in cm
Height height at
shoulder in cm
Skull width of skull
of white body markings:
1 = chest only, 2 = chest & rump, 3=none
Define a target population for
the data outlined above.
If you wished to compare the
general health of Devils with the tumours to the general health of Devils
without the disease but you only had the resources for a vet to examine 20 of
the Tasmanian Devils in this study, give a detailed explanation of how you
would decide which 20 animals to examine.
Write down all the categorical variables and indicate
whether they are nominal or ordinal.
Indicate a graphical display which could be constructed from the variables
described above to:
i. determine whether skull size is dependent on a Tasmanian Devil’s
ii. compare weights of male and female Tasmanian Devils
iii. determine whether body markings are associated with whether or not a
Tasmanian Devil contracts the disease
The weights of mature male Tasmanian
Devils are normally distributed with a mean of 11kg and standard deviation of
0.8kg. Use this information to answer the following questions. You
must show your working for these questions. You can type the formulae for your
answers on one line, for example: z=(y-m)/s or z=(y-bar-m)/(s/Ön), or, if you are a more confident Word user you can use
the equation editor in Word to form your equations. Alternatively, you can
include your (neat!) hand-written equations (and diagrams if you wish) by
photographing them so that you have the images saved as picture files and then pasting these into your solution.
conducting a study of Tasmanian Devils wants to determine the effects of weight
on overall health. He intends to sample
mature male Tasmanian Devils which weigh at least 10.5kg. If 100 mature male Tasmanian Devils are
selected at random, how many are expected to meet the requirement for his
breeding programme has been designed for mature male Tasmanian Devils. Only
those with weights among the heaviest 3% are to be included in the
programme. What is the lightest weight a
mature male Tasmanian Devil can have to be eligible for this breeding
The ideal body
weight for a mature, adult male Tasmanian Devil is between 10.2 kg and 12 kg.
Find the percentage of mature adult male Tasmanian Devils which are in the
ideal weight range.