Download JNTUH MCA 1st Sem R17 2021 July-August 841AD Probability And Statistics Question Paper

Download JNTUH (Jawaharlal nehru technological university) MCA (Master of Computer Applications) 1st Sem (First Semester) Regulation-R17 2021 July-August 841AD Probability And Statistics Previous Question Paper




R17

Code No: 841AD















2021

JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD

MCA I Semester Examinations, July/August - 2021

PROBABILITY AND STATISTICS

Time: 3 Hours















Max.Marks:75

Answer any five questions

All questions carry equal marks

- - -

1.a)

Two digits are selected at random from the digits 1 through 9.

i) If the sum is odd, what is the probability that 2 is one of the digit selected.

ii) If 2 is one of the digits selected, what is the probability that the sum is odd?

b)

A fair coin is tossed until a head or five tails occurs. Find the expected number of tosses
of the coin.



















[8+7]


2.a)

State and prove Boole's inequalities

b)

A, B, C in order toss a coin. The first one to toss head wins the game. What are the
probabilities of winning, assuming that the game may continue indefinitely?

[7+8]


3.a)

A continuous random variable X has the probability density function



f x

2x,

if

0 x 1





0,

otherwise

1

3

1

Find the cumulative distribution function for X. Also find P

X

and P X



4

4

2

b)

Find the probability of getting 1 or 4 or 5 or 6 in throwing a die 5 to 7 times among
9 trials using normal distribution.













[8+7]


4.

Show that for normal distribution the quartile deviation, mean deviation and standard
deviation are approximately 10:12:15.











[15]


5.a)

Determine the mean and standard deviation of the sampling distribution of means of
300 random samples each of size 36 are drawn from a population of size 1500 which is
normally distributed with mean 22.4 and standard deviation 0.048, if sampling is done
i) with replacement and ii) without replacement.

b)

Construct 95% confidence interval for the true proportion of computer literates if 47 out
of 150 persons from rural areas are computer literates.







[8+7]





6.a)

A normal population has a mean 0.1 and a standard deviation of 2.1. Find the probability
that the mean of simple sample of 900 members will be negative.

2021

b)

In a study conducted for 500 days, only on 4 days it was recorded that `lead' content in a
famous river exceeded 200mg/cm. Construct an upper 99% confidence limit for the
probability that the `lead' content in the river will exceed 200mg/cm on any one day.


[7+8]


7.a)

A briefcase manufacturing company claims that 80% of executives carried briefcases
produced by them. Verify its claims if in a random sample of 900 executives, 675 used
the company's briefcases. Use 5% level of significance.

b)

Explain, stating clearly the assumptions involved, the t-test for testing the significance of
the difference between the two sample means.









[7+8]


8.

The tangent of the angle between two regression lines is 0.6 and if x= 1y, find the

2

correlation coefficient between x and y.











[15]




---ooOoo---




This post was last modified on 16 March 2023