1.Suppose it is
known that in a certain population 10 percent of the population is colour
blind. If a random sample of 25 people is drawn from this population, find the
probability that
a) five or
fewer will be colour blind
b) six or more
will be colour blind
c) between six
and nine will be colour blind
d) two, three
or four will be colour blind
2.Suppose that
24 percent of a certain population have blood group A. for a sample of 25
people drawn from this population, find the probability that
a) Exactly
three will have group A
b) Three or more will have group A
c) Fewer than
three will have group A
d) Exactly five
will have group A
3. A hospital
administrator, who has been studying daily emergency admissions over a period
of several years, has concluded that they are distributed according to the
poisson law. Hospital records reveal that emergency admissions have averaged
three per day during this period. Find the probability that
a. exactly two
emergency admissions will occur on a given day.
b. no emergency
admission will occur on a given day.
c. either three
or four emergency cases will be admitted on a given day.
4. If the mean
number of serious accidents per year in a large factory (where the number of
employees remain constant ) is five, find the probability that in the current
year there will be
a. exactly
seven accidents.
b. ten or more
accidents.
c. No
accidents.
d. Fewer than
five accidents.
5. If the total
cholesterol value for a certain population is approximately normally
distributed with a mean of 200mg/100ml. And a standard deviation of 20mg/100ml.
Find the probability that an individual picked at random from this population
will have a cholesterol value
a. Between 180
and 200mg/100ml.
b. Greater than
225mg/100ml.
c. Less than
150mg/100ml.
d. Between 190
and 210mg/100ml
6. Average wt
of baby at birth is 3.05 kg with the sd of 0.39 kg. if the birth wts follow
normal distribution will you take
a. wt of 3.9 kg
as abnormal?
b. wt of 2.5 kg
as normal?
7. Menstrual
cycle in women following normal distribution has mean of 28 days and sd of 2
days. How frequently would you expect a menstrual cycle of
a. more than 30
days?
b. less than 20
days?
8. A researcher was interested to determine
if urine levels of a certain chemical in
preterm infants with late metabolic acidosis and preterm infants without the
condition differs. The mean, s. d. and sample sizes are as follows:
Sample

n

Mean

S

With condition

35

8.5

5.5

Without condition

40

4.8

3.6

9. A health
researcher wants to estimate the mean hb level in the community. Preliminary
information is that this mean is about 150 mg/l with sd of 32 mg/l. if a
difference of up to 5 mg/l in either side in the estimate can be tolerated, how
many subjects should be included in the study?
10. An intervention
programme for tobacco users is to be implemented in certain community. Find the
required sample size when the proportion of tobacco user in the community is
reported to be 20% by some other study and a difference of upto 3 in either
side is tolerable.
11. In a length
of hospitalization study conducted by several cooperating hospitals, a random
sample of 64 peptic ulcer patients was drawn from a list of all peptic ulcer
patients ever admitted to the participating hospitals and the length of hospitalization per admission was determined
for each. The mean length of stay was found to be 8.25 days. If the population
s. d. is known to be 3 days, can it be concluded that the mean hospital stay is
more than 7 days, less than 9 days and different than 7 days.
In the above
problem, if population SD is not known and sample SD is 3 days and sample size
is 25 records of patients, solve for all three conditions.
12. Protoporphyrin
levels were measured in two samples of subjects. Sample 1 consisted of 50 adult
male alcoholics with ringed sideroblasts in the bone marrow. Sample 2 consisted
of 40 apparently healthy non alcoholic males.
Can we conclude
that protopophyrin levels are higher in alcoholic population than in non
alcoholic?
The mean and SD
were
Sample

Mean

SD

Sample
number

1

340

250

50

2

45

25

40

In the above
problem if SDs are sample SDs and sample sizes are 22 for both samples apply t
test for unequal variances and equal variances
13. Researchers
wish to know if the data they have collected provide sufficient evidence to
indicate a difference in mean serum uric acid levels between normal individuals
and individuals with mongolism at 5% level. The data are as follows:
Sample

n

Mean

Mongoloids

12

4.5
mg/100ml

Normal
individuals

15

3.4
mg/100ml

a)
Let the populatiom s. d. for both is 1, solve using z
test.
b)
Let the sample s. d. for both is 1, assume equality of variances and solve. Assume
unequal variances and solve.
14. Can we
conclude that chronically ill children tend on average, to be less self
confident than healthy children? A test designed to measure self confidence was
administered to 32 chronically ill and 32 healthy children. The mean scores and
s. d. were as follows.

Mean

S

Ill
group

22.5

4.1

Well
group

26.9

3.2

15. A group of
350 adults who participated in a health survey were asked whether or not they
were on diet. The responses by sex are as follows:

Sex




Male

Female

Total

On
diet

14

25

39

Not
on diet

159

152

311

Total

173

177

350





Do these data
suggest that being on diet is dependent on sex? Let a =. 05
16. A sample of
500 college students participated in a study designed to evaluate the level of
college students’ knowledge of a certain group of common diseases. The
following table shows the students classified by major field of study and level
of knowledge of group of diseases.

Knowledge
of disease




Major
field

Good

Poor

Total


Premedical

31

91

122


Other

19

359

378


Total

50

450

500


17. A study of
190 pregnancies yielded the following results on the relationship between
hypertension of mother and a certain complication of pregnancy.
Mother hypertensive
A
certain complication of pregnancy

Yes

No

Total

Present

23

55

78

Absent

12

100

112

Total

35

155

190

Do these data
suggest that the two conditions are not independent?
18. Determine
if there is association between scabies amongst the school children and the
socio economic status.

Socio
economic status


Scabies
status

I

II

III

IV

V

Total

With
scabies

23

127

640

806

63

1659

Without
scabies

427

1573

7560

7526

541

17627

Total

450

1700

8200

8332

604

19286

2 comments:
where are the answers, the solutions ?
I'd like to have the solutions for #4a,4c
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