6. | Attempt any five of the following choose the correct alternative, stating proper reason: | 2x5=10 | |
| (a) | From a pack of 52 cards, the probability of drawing an ace of a diamond is: | | (0) |
| (b) | Two identical dice are tossed. The probability that the same number will appear on each of them is: | | (0) |
| (c) | If P(A) = 0.4, P(A U B) = 0.7 then for two independent events A and B, P(B) is (i) | 0.5 | (ii) | 0.75 | (iii) | 0.3 | (iv) | 0.2 | | | (0) |
| (d) | The mean of a binomial distribution is 12 and its variance is 9. Then the parameters (n, p) are given by (i) | | (ii) | | (iii) | | (iv) | None of these | | | (0) |
| (e) | In a Poisson distribution if x is a variate with parameter 1, then the probability (3 < x < 5) is given by for e = 2.7182) (i) | 0.0153 | (ii) | 0.153 | (iii) | 0.1055 | (iv) | None of these | | | (0) |
| (f) | For a normal distribution if mean is m, median is m0 and mode is mo’ then we get (i) | m > m0 > mo’ | (ii) | m < m0 < mo’ | (iii) | m = m0 = mo’ | (iv) | none of these | | | (0) |
| (g) | For a random variable x, then p.m.f is: f(x) = axi x = 1, 2, 3, ......, n or x = 0 otherwise. then the expectation of x is (i) | | (ii) | | (iii) | | (iv) | none of these | | | (0) |
| (h) | While studying a set of pairs of reated variates, the following results are obtained: N = 100. Σxi = 57, Σyi = 43, Σ(xi – | x | )2 = 169, Σ (y — | y | )2 = 64, |
Σ (xi — | x | ) (y — | y | ) = 101 Then correlation coefficient is equal to |
(i) | 0.79 | (ii) | 0.97 | (iii) | 1.00 | (iv) | —0.563 | | | (0) |
| (i) | In a sample of 400 parts manufactured by a factory, the number of defective parts was found to be 28. the company, however, claimed that only 4% of their products is defective. The S.E. is given by: (i) | 0.0198 | (ii) | 0.0098 | (iii) | 0.098 | (iv) | 0.98 | | | (0) |
| (j) | Describe a method of drawing sample without replacement of size 3 from a population of size 11. | | (0) |
7. | (a) | A bag contains 5 red and 3 black balls and the second one 4 red and 5 black balls. One of these is selected at random and draw of two balls is made from it. What is the probability that one of them is red and other is black? | 5 | (0) |
| (b) | In an examination 50% and 40% of the students, failed in Mathematics and Accountancy respectively while 20% failed in both the subjects. A student is selected at random. Find the probabilities that: (i) | The students failed in Accountancy if known that he failed in Mathematics; | (ii) | The student failed in exactly one subject. | | 3+2 | (0) |
8. | (a) | If the distribution of marks received in an examination is normal, 44% of the candidates got marks below 61.4% of candidates got marks above 80, find the percentage of candidates received above 65 marks. (Given that | | ∫ e— 1/z t2 | dt = 0.06, 0.10, 0.46 according as x = 0.15, 0.25, 1.75) | | 5 | (0) |
| (b) | An oil exploration firm funds that 4% of the test wells it drills yield a deposit of natural gas. If the firm drills 5 wells. What is the probability that: (i) exactly 2 wells (ii) at least one well yield gas? | 3+2 | (0) |
9. | (a) | The average number of articles produced by two machines per day are 200 and 250 with s.d. 20 and 25 respectively on the basis of records of 25 days production. Can you regard both the machines equally efficient at 1% level of significance? | 5 | (0) |
| (b) | In a survey of 200 boys of which 75 were intelligent, 40 had skilled fathers, while 85 of the unintelligent boys had unskilled fathers. Do these figures support the hypothesis that skilled fathers have intelligent boys? Use χ2test. Value of χ2 for 1 d.f. at 5% level is 3.84. | | 5 | (0) |
10. | (a) | The regression equation of production (x) on capacity utilisation (y) of a certain firm is 3x — 2.76y + 102.30 = 0. The average capacity utilisation of the firm was 70% and the variance of capacity utilisation is (9/16)th of the variance of production. Find the average production and coefficient of correlation between production and capacity utilisation. | 5 | (0) |
| (b) | The Alpha flower shop promises its customers delivery within four hours on all flower orders. All flowers are purchased on the prior day and delivered to Alpha by 8 A. M. next day. Alpha’s daily demand of roses is as follows: Dozen of Roses | : | 7 | 8 | 9 | 10 | Probability | : | 0.1 | 0.2 | 0.4 | 0.3 |
Alpha purchases roses for Rs. 10.00 per doze and sells them for Rs. 30.00. All unsold roses are donated to a local hospital. How many dozen of roses should Alpha order each evening to maximise its profits? What is the optimum expected profit? | 5 | (0) |
11. | (a) | A population consists of the numbers 1, 5, 3, 7, 9. consider all possible samples of size two which can be drawn without replacement from this population. Find the mean of the sampling distribution of mean. | 5 | (0) |
| (b) | Suppose a departmental store manager is studying the inventory situation and is interested in generating possible sales for 10 days. Assuming that the number of sales per day is Poison with mean 5,generate 10 days of sales by Monte Carlo method using the following random numbers: 1048 1792 | 0150 2368 | 1101 4657 | 5360 3255 | 2011 9585 | 8164 3933 | 7916 0995 | 4669
| | 5 | (0) |