Screenshot 2024-02-07 at 3.23.37 PM
Screenshot 2024-02-07 at 3.23.37 PM
Screenshot 2024-02-07 at 3.23.37 PM
c) 2
Suppose that X has a Poisson distribution. If 𝑃(𝑋 = 2) = 3 𝑃(𝑋 = 1). Evaluate [2]
P(x=0).
d) If X is a continuous random variable whose probability density function is given [2]
by
𝑘(5𝑥 − 2𝑥 2 ), 0 ≤ 𝑥 ≤ 2
f(x) = { . Then P(x>1) is
0, 𝑜𝑡ℎ𝑒𝑟𝑤𝑖𝑠𝑒
e) The joint probability density function of two variables (X, Y) is given by [2]
𝑘𝑒 −(𝑥+𝑦) : 0<𝑦≤𝑥<∞
f(x,y) = { then find K.
0, 𝑜𝑡ℎ𝑒𝑟𝑤𝑖𝑠𝑒
f) The uniform random variable has mean 1.5 and variable 27/4, then find [2]
P(X>0).
g) Find the value of the finite population correction factor for the size of sample [2]
10 and the size of population 1000.
h) Find the maximum error so that one can expect to make with the probability [2]
0.90 when using the mean of a random sample of size 64 to estimate the mean
of population with variance 2.56.
i) Using Fermat factorization find the factor of the integer 11021. [2]
4) a) 20% of items produced from a factory are defective. Find the probability [5+5]
that in a sample of 5 chosen at random, i) none is defective, ii) one is
defective, iii) P(1<X<4).
b) If the variance of Poisson variable is 1.8, then find i) P(X>1) ii) P(X=5) iii)
P(0<X<5).
(OR)
5) In a distribution exactly normal, 10.03% of the items are under 25-kilogram [10]
weight and 89.97% of the items are under 70-kilogram weight. What are the
mean and Standard deviation of the distribution?
6) The joint density function of the random variables (x, y) is given as follows [10]
2
𝑓(𝑥, 𝑦) = {𝑐𝑥 𝑦 ∶ 0 ≤ 𝑥, 𝑦 ≤ 1 find i) Cov (x, y) ii) E[X+Y]
0 ∶ 𝑂𝑡ℎ𝑒𝑟𝑤𝑖𝑠𝑒
(OR)
7) a) Calculate the rank coefficient of correlation for the following data. [10]
X 50 50 55 60 65 65 65 60 60 60
Y 11 13 14 16 16 15 15 14 13 13
8) A company claims that its bulbs are superior to those of its main competitor. [5+5]
If a study showed that a sample of 40 bulbs have a mean life time of 647hrs
of continuous use with standard deviation of 27 hrs. while a sample of 40
bulbs made by its main competitor had a mean life time of 638 hrs of
continuous use with standard deviation of 31 hrs. test the significance
difference between the difference of means at 5% level.
(OR)
9) A population consists of 5 numbers 2, 6, 8, 11, 12. Consider all the samples of [10]
size 2 that can be taken from the population with replacement, then find
i) Mean of Population, ii) Standard Deviation of the population, iii) Mean of
sampling distribution of means, iv) Standard Deviation of sampling
distribution of means, v) Standard error.
10) a) find the solution of system of congruences 𝑥 ≡ 1 (𝑚𝑜𝑑 2), 𝑥 ≡ [5+5]
2 (𝑚𝑜𝑑 3), 𝑥 ≡ 3 (𝑚𝑜𝑑 5).
b) Solve the linear congruences 9𝑥 ≡ 21 (𝑚𝑜𝑑 30).
(OR)
11) a) Using Euclidean algorithm calculate g.c.d. (12378, 3054) and obtain [10]
integers x and y satisfying g.c.d. (12378, 3054) = 12378x+3054y.