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In a sample of 49 adolescents who served as the subjects in an
immunologic study, one variable of
interest was the diameter of skin test reaction to an antigen. The sample mean
and standard deviation
were 21 and 11mm erythema, respectively. Can it be concluded from these
data that the population
mean is less than 30? Let alpha = 0.5
The purpose of a study by Lugli_e et al. (A-5) was to investigate the oral
status of a group of patients
diagnosed with thalassemia major (TM). One of the outcome measures was
the decayed, missing, and
filled teeth index (DMFT). In a sample of 18 patients the mean DMFT index
value was 10.3 with a
standard deviation of 7.3. Is this sufficient evidence to allow us to conclude
that the mean DMFT
index is greater than 9.0 in a population of similar subjects? Let alpha = 0.1
The table below gives the scores of Students on a English Examinations
under KCSE
Student
1
2
3
4
5
6
7
8
9
Oral test
B-
B+
B
A-
A
B
C+
B
C-
Composition
10
21
22
19
17
14
13
16
12
Literature
34
76
74
60
68
44
45
53
43
(Composition test is out of 30 and literature test is out of 100 marks)
(a) Calculate the value of the most appropriate measure of correlation between the results
in the oral and composition tests, justifying your choice of measure. Interpret the value you
obtain.
(b) Calculate the value of the most appropriate measure of correlation between the results in
the composition and literature tests, justifying your choice of measure. Interpret the value
you obtain.
List down 5 of Random Sampling and 5 examplesof Non Random Sampling. Also, identify if what particular random sampling and non sampling techniques are being applied.
First Column
Random Sampling
1.
2.
3.
4.
5.
Second Column
Non Random Sampling
1.
2.
3.
4.
5.
d) A random sample of size 36 was taken from a population distributed as Nμ,3.92.The value of the sample x was 15.6. i. Find a 90% confidence interval for μ. (5mks)
It is believed that value of μ is 17. Use your confidence interval to comment on this belief.(2mks)
- Using the provided information below,
x=33.2 , x2=131.67, y=30.78 , y2=116.52, xy=119.8 , and n=10
- Find the sample correlation coefficient r (4mks)
- Find the co-efficient of determination (2mks)
study was made of a sample of 25 records of patients seen at a chronic
disease hospital on an
outpatient basis. The mean number of outpatient visits per patient was 4.8,
and the sample standard
deviation was 2. Can it be concluded from these data that the population mean
is greater than four
visits per patient? Let the probability of committing a type I error be .05. What
assumptions are
necessary?
A study by Thienprasiddhi et al. (A-4) examined a sample of 16 subjects
with open-angle glaucoma
and unilateral hemifield defects. The ages (years) of the subjects were:
62 62 68 48 51 60 51 57
57 41 62 50 53 34 62 61
Can we conclude that the mean age of the population from which the sample
may be presumed to have been drawn is less than 60 years? Let alpha = 0.5
7.2.2 A study by Thienprasiddhi et al. (A-4) examined a sample of 16 subjects
with open-angle glaucoma
and unilateral hemifield defects. The ages (years) of the subjects were:
62 62 68 48 51 60 51 57
57 41 62 50 53 34 62 61
Can we conclude that the mean age of the population from which the sample
may be presumed to have been drawn is less than 60 years? Let alpha = 0.5
Conduct P-value method
The Mathematics Department in a certain university is conducting a study to determine how long it takes its graduates to find a job. A sample of 80 graduates was surveyed and it was found out that the average time it has taken a graduate to find a new job is 2.5 months, with a standard deviation of 2 months. Is there a sufficient evidence to conclude that the graduate of this department takes on the average more than two months to find a job? Use the 90% confidence level.
Consider all sample siza 5 fro this population 2 5 6 8 10 12 13 compute the mean u and standard deviation ó of the population
#340153 on Dec 2023