Quiznetik

Statistics | Set 2

1. Study of scatteredness of observations is known as ________

Correct : A. Measure of dispersion

2. Standard deviation of first 50 natural number is__________

Correct : C. 14.43

3. Calculate coefficient of variation c)V.) for the following data 2,4,8,6,10 and 12 is____________

Correct : A. 48.86

4. Calculate Standard deviation for the following sample data 2,4,6,8,10 and 12. Is________

Correct : C. 3.42

5. Standard deviation is always___________

Correct : B. Positive

6. The arithmetic average of the absolute deviation of a series known as the________

Correct : C. Mean deviation

7. The average of the squared deviations about the arithmetic mean for a set of numbers is__________

Correct : D. Variance

8. The measure of dispersion which is expressed in terms of the nits of observations__________

Correct : A. Absolute measure

9. If the difference of the third and first quartiles is divided by the sum of the third and first quartiles then it is known as __________

Correct : C. Coefficient of quartile deviation

10. The average of squared deviations about the arithmetic mean for a set of numbers is called___________

Correct : D. Variance

11. The measure of dispersion which is expressed in terms of the units of the observations I called________ Absolute measure

Correct : A. Variance

12. If the difference of the third and first quartile is divided by the sum of the third and first quartile then it is known as__________

Correct : C. Coefficient of quartile deviation

13. The scatter in a series of values about the average is called___________

Correct : B. Dispersion

14. The measurements of spread or scatter of the individual values around the central point is called________

Correct : A. Measures of dispersion

15. The measures used to calculate the variation present among the observations in the unit of the variable is called___________

Correct : C. Absolute measures of dispersion

16. The measures used to calculate the variation present among the observations relative to their average is called_______

Correct : D. Relative measures of dispersion

17. The degree to which numerical data tend to spread about an average value called________

Correct : C. Variation

18. The measures of dispersion can never be__________

Correct : C. Negative

19. If all the scores on examination cluster around the mean, the dispersion is said to be________

Correct : A. Small

20. If there are many extreme scores on all examination, the dispersion is____________

Correct : A. Large

21. Given below the four sets of observations. Which set has the minimum variation?____________

Correct : D. 48, 49, 50, 51, 52

22. Which of the following is an absolute measure of dispersion?___________

Correct : C. Standard deviation

23. The measure of dispersion which uses only two observations is called___________-

Correct : C. Range

24. The measure of dispersion which uses only two observations is called__________

Correct : A. Range

25. In quality control of manufactured items, the most common measure of dispersion is___________

Correct : A. Range

26. The range of the scores 29, 3, 143, 27, 99 is_____________

Correct : B. 143

27. If the observations of a variable X are, -4, -20, -30, -44 and -36, then the value of the range will be_________

Correct : D. 48

28. The range of the values -5, -8, -10, 0, 6, 10 is___________

Correct : D. 20

29. If the maximum value in a series is 25 and its range is 15, the maximum value of the series is___________

Correct : B. 15

30. Half of the difference between upper and lower quartiles is called___________

Correct : C. Mean deviation

31. If Q3=20 and Q1=10, the coefficient of quartile deviation is___________

Correct : B. 1/3

32. Which measure of dispersion can be computed in case of openend classes?___________

Correct : C. Quartile deviation

33. The sum of absolute deviations is minimum if these deviations are taken from the_____________

Correct : C. Median

34. The mean deviation is minimum when deviations are taken from____________

Correct : D. Zero

35. If Y = ax ± b, where a and b are any two numbers but a 0, then M.D(Y) is equal to__________

Correct : D. M.D(Y) + M.D(X)

36. The mean deviation of the scores 12, 15, 18 is_____________

Correct : B. 0

37. Mean deviation computed from a set of data is always____________

Correct : A. Negative

38. The average of squared deviations from mean is called_____________

Correct : B. Variance

39. The sum of squares of the deviations is minimum, when deviations are taken from__________

Correct : C. Median

40. Which of the following measures of dispersion is expressed in the same units as the units of observation?__________

Correct : C. Coefficient of variation

41. Which measure of dispersion has a different unit other than the unit of measurement of values________

Correct : B. Standard deviation

42. Which of the following is a unit free quantity___________

Correct : D. Arithmetic mean

43. If the dispersion is small, the standard deviation is____________

Correct : C. Small

44. The value of standard deviation changes by a change of__________

Correct : D. None

45. The standard deviation one distribution divided by the mean of the distribution and expressing in percentage is called_____________

Correct : A. Coefficient of Standard deviation

46. The positive square root of the mean of the squares of the deviations of observations from their mean is called____________

Correct : D. Coefficient of variation

47. The variance is zero only if all observations are the___________

Correct : D. Same

48. The standard deviation is independent of_____________

Correct : B. Change of scale of measurement

49. If there are ten values each equal to 10, then standard deviation of these values is___________

Correct : C. 10

50. Which is a method of measuring correlation?________

Correct : D. Both of these

51. A scatter diagram is________

Correct : D. A graph showing x and y values

52. If there exists any relation between the sets of variables, it is called__________

Correct : C. Correlation

53. Perfect correlation is one Perfect correlation is one in which_________

Correct : C. None of these

54. Which of the following measurement scales is required for the valid calculation of Karl Pearson’s correlation coefficient?__________

Correct : A. Ordinal

55. Which of the following point is not related with the utility of correlation?________

Correct : D. All of these

56. Which of the following is not cause of the correlation?____________

Correct : D. None of these

57. Which of the following is the highest range of r?__________

Correct : C. -1 and 1

58. When the correlation coefficient between x and y is positive, then as variable x decreases, variable y Remains the same________

Correct : B. Decreases

59. Which of the following is most likely to be an inverse relationship?__________

Correct : B. Between price increase and demand for a certain product

60. Which of the following measurement scales is required for the valid calculation of spearman correlation coefficient?_____________

Correct : B. Interval

61. The ratio of the average deviations is called__________

Correct : A. Regression

62. What will be the range of r when we find that the dependent variable increases as the independent variable increases?__________

Correct : C. 0 .1 to 1

63. Which of the following is true if the estimating equation has to be a perfect estimator of the dependent variable?______________

Correct : D. B and C

64. When a multiple correlation coefficient R 1.23 =1 , then R 2.13 is________

Correct : A. 1

65. When a multiple correlation coefficient r 1.2=1, then it shows __________

Correct : C. Perfect relationship

66. When the two regression line coincide, then r is_________

Correct : C. 0

67. Statistics branches include__________

Correct : D. Both A and B

68. The variables whose calculation is done according to the weight, height and length and weight are known as__________

Correct : C. Continuous Variables

69. The number of accidents in a city during 2010 is___________

Correct : B. Continuous variable

70. The correlation coefficient is used to determine________

Correct : C. The strength of the relationship between the x and y variables

71. If there is a very strong correlation between two variables then the correlation coefficient must be _______

Correct : B. much smaller than 0, if the correlation is negative

72. In regression, the equation that describes how the response variable (y) is related to the explanatory variable (x) is___________

Correct : B. the regression model

73. The relationship between number of beers consumed (x) and blood alcohol content (y) was studied in 16 male college students by using least squares regression. The following regression equation was obtained from this study: != -0.0127 + 0.0180x The above equation implies that__________

Correct : C. each beer consumed increases blood alcohol by an average of amount of 1.8%

74. SSE can never be _____________

Correct : A. larger than SST

75. Regression modeling is a statistical framework for developing a mathematical equation that describes how __________

Correct : C. one response and one or more explanatory variables are related

76. In regression analysis, the variable that is being predicted is the __________

Correct : A. response, or dependent, variable

77. Regression analysis was applied to return rates of sparrowhawk colonies. Regression analysis was used to study the relationship between return rate (x: % of birds that return to the colony in a given year) and immigration rate (y: % of new adults that join the colony per year). The following regression equation was obtained) ! = 31.9 – 0.34x Based on the above estimated regression equation, if the return rate were to decrease by 10% the rate of immigration to the colony would________________

Correct : B. increase by 3.4%

78. In least squares regression, which of the following is not a required assumption about the error term ε? ___________

Correct : A. The expected value of the error term is one.

79. Larger values of r 2 (R2 ) imply that the observations are more closely grouped about the __________

Correct : C. least squares line

80. In a regression analysis if r 2 = 1, then ___________

Correct : B. SSE must be equal to zero

81. The coefficient of correlation____________

Correct : B. is the square root of the coefficient of determination

82. In regression analysis, the variable that is used to explain the change in the outcome of an experiment, or some natural process, is called ________

Correct : D. all of the above (a-c) are correct

83. In the case of an algebraic model for a straight line, if a value for the x variable is specified, then________

Correct : A. the exact value of the response variable can be computed

84. A regression analysis between sales (in $1000) and price (in dollars) resulted in the following equation: ! = 50,000 - 8X The above equation implies that an ________

Correct : D. increase of $1 in price is associated with a decrease of $8000 in sales

85. In a regression and correlation analysis if r 2 = 1, then ___________

Correct : D. SSR = SST

86. If the coefficient of determination is a positive value, then the regression equation__________

Correct : C. could have either a positive or a negative slope

87. If two variables, x and y, have a very strong linear relationship, then ____________

Correct : C. there might not be any causal relationship between x and y

88. If the coefficient of determination is equal to 1, then the correlation coefficient _______

Correct : B. can be either -1 or +1

89. In regression analysis, if the independent variable is measured in kilograms, the dependent variable ______

Correct : D. can be any units

90. The data are the same as for question 4 above. The relationship between number of beers consumed (x) and blood alcohol content (y) was studied in 16 male college students by using least squares regression. The following regression equation was obtained from this study: != -0.0127 + 0.0180x Suppose that the legal limit to drive is a blood alcohol content of 0.08. If Ricky consumed 5 beers the model would predict that he would be____________

Correct : B. 0.0027 below the legal limit

91. If the correlation coefficient is 0.8, the percentage of variation in the response variable explained by the variation in the explanatory variable is____________

Correct : B. 80%

92. If the correlation coefficient is a positive value, then the slope of the regression line ___________

Correct : D. can not be zero

93. If the coefficient of determination is 0.81, the correlation coefficient __________

Correct : A. is 0.6561

94. A fitted least squares regression line ____________

Correct : B. is evidence for a cause-effect relationship between x and y

95. Regression analysis was applied between $ sales (y) and $ advertising (x) across all the branches of a major international corporation. The following regression function was obtained) ! = 5000 + 7.25x If the advertising budgets of two branches of the corporation differ by $30,000, then what will be the predicted difference in their sales? __________

Correct : A. $217,500

96. Suppose the correlation coefficient between height (as measured in feet) versus weight (as measured in pounds) is 0.40. What is the correlation coefficient of height measured in inches versus weight measured in ounces? [12 inches = one foot; 16 ounces = one pound] _______

Correct : A. 0.40

97. Assume the same variables as in question 28 above; height is measured in feet and weight is measured in pounds. Now, suppose that the units of both variables are converted to metric (meters and kilograms). The impact on the slope is__________

Correct : A. the sign of the slope will change

98. Suppose that you have carried out a regression analysis where the total variance in the response is 133452 and the correlation coefficient was 0.85. The residual sums of squares is____________

Correct : A. 37032.92

99. In a regression analysis if SSE = 200 and SSR = 300, then the coefficient of determination is ___________

Correct : B. 0.6000