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PATEL GROUP OF INSTITUTIONS. BCA III ( SM ) 1) Quartile divides into four equal parts. 2) Measure of dispersion are a. Range b. Mean deviation c. Quartile deviation d. Standard deviation 3) Which measure of dispersion is ideal – “standard deviation” 4) Standard deviation is independent of change of origin but not of scale 5) Value of correlation coefficient is between -1 or +1. 6) The value of r2 lie between 0 & 1 7) Two regression line intersect each other mean x and mean y 8) There are two types of classification qualitative and quantitative 9) Mean is an ideal average 10) the relative measure of dispersion based on standard deviation is coefficient of variance 11) if two variables are perfectly positively correlated r = +1 12) in rank of correlation if ∑d2 = 0, r=1 13) examples of positive correlation a. heights and weights b. income and expenditure 14) examples of negative correlation a. demand and price b. volume and pressure of perfect gas 15) when median is used ? a. when we want to find positional average median is used. It is not affected by extreme observations. 16) When measure of dispersion is used a. How the individual values is differ from the central value. 17) Q1<Q2<Q3. 18) Coefficient of variance dispersion is used to compare two series. Class Boundaries : In case of inclusive type classification there is need to convert the data into a continuous distribution by applying correction for continuity for determining new classes of exclusive type. The upper and lower class limits of the new “exclusive type “ classes as called class boundaries. Upper class boundaries = upper class limit + (½) d Lower class boundaries = Lower class limit - (½) d Where d/2 = correction factor Class interval : the difference between lower limit and upper limit of the class is called its class interval. Class frequency :number of times particular values of the variable is repeated in given class is called class frequency. Question : State the empirical relationship between mean, median and mode Ans : in case of symmetrical distribution mean, median and mode are coincide. i.e Mean= Median=Mode In asymmetrical distribution, mean and mode usually lie on the two ends and median lies in between them and they obey the following empirical relationship. Mode = 3 Median – 2Mean