Dhaka International [.!nrversity
Dept" of Cornputer Scienee & Engineering
Semester Final Examination (spring-2016)
Batch No.: 43'd (Evening) Semester: 4th
Course Code: MATH-
Time: 2.5
201
Course Title: Statistical Methods and Probability
Full Marks: 50
Houps
Group-A
Answer any Two of the following questions
1,.
(a) Mention under what conditions a distribution will be binomial.
(b) Prove that-"for binomial distribution mean is greater than variance."
(c) The incidence of occupational disease in an industry is such that the workers
have a 25% chance of suffering from it. What is the probability that out of
workers chosen at random(i) Five or more will suffer from the disease
(ii) Exactly'four workers suffer from it.
2.
6
B
(a) Write down some properties of Poisson distribution.
(b) Find E(x) and V(x) for Poisson distribution.
(c)The chance of a traffic accident in a day in a street of Rangpur city is 0'002.
On how many days out of total L500 days we can expect(i) No accident
(ii) More than three accidents.
3.
2"5
(a)Write down some properties of normal distribution.
(b) Calculate total probability of normal distribution.
(c) Find mean and variance of normal distribution.
4
3
5'5
4
3'5
3
6
Group-B
Answer any One of the following questions
4.
5.
(a)Define skewness. How would you measure different types of skewness'
(b) Define kurtosis. How would you measure different types of kurtosis.
(c) The first four moments of a distribution about the value 5 are -2.5, 20, -31
and 110. Find the moments about the point X=2.
(a) Define regression. write down some properties of regression.
(b)Prove that-"correlation of co-efficient lies between -1 and 1."
(c) Discuss different types of correlation.
1+3=4
1+3=4
4
1-+3=4
4
4'5
GrouL-C
Compulsory
6.
1
(a)Define multiplicative law of probability for two independent events.
(b) Define conditional probability. Derive Baye's theorem by using it.
(c) a coin is tossed 4 times. Find the following
., (i) 0 head
'
(ii) 2 heads
(iii) At'least 2 heads
(iv) At most 2 heads
probabilities-
4
3'5
6