Statistics for Business — DU B.A. (Hons.) Business Economics (BBE) Previous Year Question Papers

(i) From the following data draw ogives and calculate Median marks. (ii) If 20 is subtracted from every observation in a data set, then, the coefficient of variațion of the resulting data set. is 20%. If 40 is added to every observation of the 'same data sét, then the' coéfficient of variation of the resulțing set of data is 10% Find the mean and standard deviation o the original set of data. (iti)Distinguish between dispersion and skewness, From the following data calculate Kari Pearson's 'Coefficient of skewness.. (iv) Pearson's Coefficient of Skewness for a "distribution iș 0.4 and Coefficient of variation is 30%. Its mode is 88. Find the mean and the median. (i) The probability that a contractór will get a plumbing contract is 2/3 and the probability that he will not get an electric contract is 5/9:If the probability getting at least one contact is 4/5, what is the probability that he will get both the contraçts? Are the event "› of getting at plumbing contract and getting an electric contract independent? (ii) Define Probability. Discuss the importance of probability in decision making. (iit) (a) Find out correlation coefficient of X and Y. (b) State the relationship between coefficient of correlation and regression coefficients. (i) (a) , the process of computing the correlation coefficient between two variables X and Y from 12 paired observations, a data analyst obtained the following summary statistics: It was, however, discovered at the time of checking that the pair (X = 11, Y = 4), was copied wrongly, the correct values being (X = 10, Y, = 14) After making necessary corrections find; 1. the two regression coefficients. 2u the two regression equations. 3. the correlation coefficients. (b) A correlation coefficient of Ö.5 does not mean that 50% of the data are explained. Comment. (ii) (a) Given that the variance of x=9 and the regression lines are 8x-10y+66=0,40x- 8y=214, find the coefficient of orrélation between x and y. Also fine he standard deviation of Y (b) If all thé points in 'a scatter diagram lie exactly on the regression line, the two variables are perfectly correlated. (iii)A multiple-chóice test consists of 8 question ith answers a where only question by rolling a balanced dice and checking the first answer if he gets 1 or2, The second answer if he gets 3 or 4 and the third answer If he gets 5 or, 6. To get a east tion, treet adepers: if there is at negative. marking; what is the probability that the student, secures a distinction. , (iv) Under what conditions can a binomial distribution be applied suppose a man takes step forward with probability 0. 25 ånd báckward with probability O. 75. Find nd backward the probability that at the end of 11 steps, he is one step away from the starting point (i) Define hypothesis testing! Distinguish between Null Hypothesis' and Alternative Hypothesis. Write in brięf the various steps required to conduct an hypothesis test?