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MATHEMATICS, STATISTICS AND PROBABILITY, HOME TEST, 1. The algebraic sum of deviations of 16 observations measured from 25 is 4. The mean of the, set is, a. 4, b.404, c.25, d.25.25, 2. The quartile deviation of daily wages of 7 persons which are Rs.12,7,11,15,17,17,25 is, a.14.5, b.13.5, c.7, d.3.5, 3. The variance of first n natural numbers is, a., , n2  1, 12, , b., , n2  1, 6, , c., , n  12n  1, 6, , d. none of these, , 4. All the students of a class performed poorly in mathematics. The teacher decided to give grace, marks of 10 to each student which of the following statistical measures will not change even, after the grace marks given, a. Mean, b. Median, c. Mode, d. Variance, 5. The mean deviation about mean of the data 7, 9,24,14,26 is, a. 7.5, b. 8, c. 7.2, d. 7, 6. If the sum of the squares of deviations of 25 observations taken from the mean 40 is 900, then, the co-efficient of variation is, a. 20%, b. 12.5%, c. 15%, d. 18%, 7. If in a distribution n=10,  x  20 ,  x  200 then the value of standard deviation of the, distribution is, a. 2, b.16, c.6, d.433., 8. A set of n values x1, x2 ,.............xn has standard deviation  . The standard deviation of n, values, x1  k , x2  k ,.............xn  k, will be, , , k, , a., b., c.   k, d. k, 9. The standard deviation of 50 values of a variable x is 15. If each value of the variable is, divided by -3, then the standard deviation of the new set of 50 values of x will be, a. 15, b. -5, c.5, d.-15, 10. Let x1, x2 , x3 , x4 , x5 be the observations with mean m and standard deviation s . The, 2, , standard deviation of the observations kx1, kx2 , kx3 , kx4 , kx5 is, a. k  s, , b., , s, k, , c. ks, , d. s, , 11. Standard deviation of first 10 natural numbers is, a.5.5, b. 3.87, c. 2.97, d. 2.87, 12. Consider the numbers 1,2,3,4,5,6,7,8,9,10. If 1 is added to each number the variance of the, number so obtained is, a.6.5, b. 2.87, c. 3.87, d. 8.25, 13. The following information relates to a sample of size 60 : x 2  18000, x  960 . The variance, , , , , , is, a.6.63, b. 16, c. 22, d. 44, 14. Coefficient of variation of two distributions are 50 and 60, and their arithmetic means are 30, and 25 respectively. Difference of their standard deviation is, a. 0, b. 1, c. 1.5, d. 2.5, 15.The geometric mean of observations 2,4,6,16 and 32 is, a.6 b.7, c.8, d.9, 16.The standard deviation of set of variables is 2.5. Now 16 is added to each observation, the, standard deviation of the new set is, a.2.5 b.6.5, c.18.5 d.none, 17.The sum of 10 items is 12 and the sum of their squares is 18. Then standard deviation will be, a.-3/5, b.6/5, c.4/5, d.3/5, 18.The median and S.D of a distribution are 20 and 4 respectively.If each item is increased by 2, the new median and S.D will be, , Absolute Learning Academy 1

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MATHEMATICS, a.22,6, b.18,4 c.18,6 d.22,4, 19.The variance of 6,8,10,12,14 is, a.1, b.8, c.12, d.16, 20.For a given distribution of marks mean is 35.16 and its standard deviation is 19.76 . The, coefficient of variation is, a.56.2, b.0.562, c.1.779, d.177.935, 21. Out of 30 consecutive numbers, 2 are chosen at random. The probability that their sum is, odd is, a) 14/29, b)16/29, c) 15/29, d) 10/29, 22. The key for the door is in a bunch of 10 keys. A man attempts to open the door by trying, keys at random discarding the wrong key. The probability that the door is opened in the fifth, trial is, a) 1/2, b)1/10, c) 3/5, d) 2/5, 23. A and B are events such that P(A)=0.4, P(B)=0.3, P(AUB)=0.5. Then P(𝐵1 ∩ 𝐴)=, a) 2/3, b)1/2, c) 3/10, d) 1/5, 24. A die is thrown and a card is selected at random from a pack of 52 playing cards. The, probability of getting an even number on the die and a spade card is, a) 1/2, b)1/4, c) 1/8, d) 3/4, 25. If A and B are two mutually exclusive events then,, a) P(A)≤P(𝐵), b)P(A)>P(B), c) P(A)<P(B), d) None of these, 26. Three integers are chosen at random from the first 20 integers. The probability that their, product is even is, a) 2/19, b)3/19, c) 17/19, d) 4/19, 27. Three houses are available in a locality. Three persons apply for the houses. Each applies for, one house without consulting others. The probability that all three apply for the same house is, a) 1/9, b)2/9, c) 7/9, d) 8/9, , Absolute Learning Academy 2