0% Correlation and regressionAdvertisements 1 / 25 Which of the following is correct? a) If there is a strong relationship between two variables, the points on the scatter diagram concentrated around a curve b) Linear regression analysis is used to calculate values of “a” and “b” in the linear cost equation c) The standard regression equation is y= a – bx d) Both (a) and (b) 2 / 25 When on scatter diagram all points cluster around a single point is called: a) No correlation b) High correlation c) Moderate correlation d) Linear correlation 3 / 25 When correlation coefficient is closer to one then: a) No correlation b) High correlation c) Moderate correlation d) Linear correlation 4 / 25 Which of the following is true about regression lines?1. It is used to obtain line of best fit between two variables.2. We can calculate fixed cost from it but not variable cost. a) Only statement 1 is correct b) Only statement 2 is correct c) Both statements are correct d) None of the above are correct 5 / 25 Which of the following statement is /are correct about correlation coefficient?1. It is always from 0 to +12. It is always from 0 to -1 a) Only statement 1 is correct b) Only statement 2 is correct c) Both statements are correct d) None of the above are correct 6 / 25 Find the coefficient of correlation between x and y if:Regression line of x on y is: 5x-4y+2=0 andRegression line of y on x is: x-5y+3=0 a) 0.4 b) -0.4 c) ±0.9 d) ±0.16 7 / 25 A medical research company has developed the following equation for regression line ofy on x (line of best fit) for a particular age group y= 6.93 +0.38x where x represent height incentimeters and y represents weight in kilogram. Using above equation, we can say that a) For each centimetre increase in height, weight will decrease by 0.38 kilogram b) For each centimetre increase in height, weight will increase by 0.38 kilogram c) For each centimetre increase in height, weight will increase by 6.55 kilogram d) For each centimetre increase in height, weight will decrease by 6.55 kilogram 8 / 25 Which of the following statements about scatter diagram is/are correct?(i) It is important to establish which variable is independent before plotting(ii) It might indicate a relationship where there is none a) Only statement 1 is correct b) Only statement 2 is correct c) Both statements are correct d) None of the above are correct 9 / 25 Which of the following is correct? a) If there is a strong relationship between two variables, the points on the scatter diagram would be concentrated around a curve b) The standard regression equation is y= a – bx c) Scatter diagram leads to correct conclusions even if there are few data points d) Both (a) and (b) 10 / 25 Which of the following is correct? a) If there is a strong relationship between two variables, the points on the scatter diagram would be concentrated around a curve b) ) Linear regression analysis can be used to estimate fixed costs and variable cost per unit from historical total cost and production data. c) The standard regression equation is y= a – bx d) Both (a) and (b) 11 / 25 If the coefficient of determination is a positive value, then the coefficient of correlation: a) Must be positive b) Must be negative c) Must be zero d) Can be positive as well as negative 12 / 25 If the value of coefficient of determination i.e r^2=0.64, it means that: a) 80% of variations in the value of y are explained by variations in the value of x b) 64% of variations in the value of y are explained by variations in the value of x c) 36% of variations in the value of y are explained by variations in the value of x d) 20% of variations in the value of y are explained by variations in the value of x 13 / 25 If the equation for regression line of y on x (line of best fit) is y=32+0.5x, then for everyunit increase in x, y would: a) Increase by 32 units b) increase by 16 units c) increase by 4.8 units d) Increase by 0.5 units 14 / 25 If the equation for regression line of y on x (line of best fit) is y=16 - 1.5x, then byincreasing every 1-unit of x the value of y would: a) Decrease by 16 units b) Decrease by 14.5 units c) Decrease by 1.5 units d) Increase by 14.5 units 15 / 25 If a = -12.57 and b = 0.35 then equation for regression line of y on x (line of best fit)would be: a) Y=-0.35+12.57x b) Y=0.35-12.57x c) Y=12.57- 0.35x d) Y= -12.57+0.35x 16 / 25 If the value of r2 is 0.25, it means that: a) 75% of the variation in the value of y is explained by variation in the value of x b) 45% of the variation in the value of y is explained by variation in the value of x c) 25% of the variation in the value of y is explained by variation in the value of x d) 14% of the variation in the value of y is explained by variation in the value of x 17 / 25 If 49% of variations in the value of y are explained by variations in the value of x thencoefficient of correlation is: a) 0.51 b) 0.70 c) 0.50 or -0.50 d) Either 0.49 or – 0.49 18 / 25 If 25% of variations in the value of y are explained by variations in the value of x thencoefficient of correlation is: a) 0.25 b) 0.75 c) 0.50 or -0.50 d) Either 0.25 or – 0.25 19 / 25 Value of r=0, indicates a) Perfect positive correlation b) Perfect negative correlation c) No correlation d) None of the above 20 / 25 Perfect positive correlation is denoted by value: a) 1 b) 0 c) Between 0.90 and 1.0 d) 1 or -1 21 / 25 Following equations are givenX+2Y+5=0X+3Y–10=0Find coefficient of correlation a) 0.8165 b) – 0.8165 c) 1.2247 d) -1.2247 22 / 25 The correlation between height and weight for adults is +0.90. it depicts height onaccount of variation in weight is: a) 90% b) 45% c) 10% d) 81% 23 / 25 Which of the following is correct? a) The coefficient of determination is the square root of the correlation coefficient. b) The coefficient of coefficient is the square of the correlation of determination. c) The coefficient of correlation explains the variations in the value of y by variations in the value of x d) The coefficient of determination explains how much variability of one factor can be caused by relationship to another related factor 24 / 25 If all the points on scatter diagram lies on the regression line, then coefficient ofcorrelation is a) 1 b) 0 c) -1 d) 1 or -1 25 / 25 If covariance(x,y)=62, standard deviation (x) = 16 and standard deviation (y)=7, “r” willbe equal to: a) 0.6435 b) 0.5536 c) 0.6235 d) 0.5235 Your score isThe average score is 54% 0% Restart quiz Advertisements
