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Statistics

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  1. 101.Consider the statistics of two sets of observations as follows: Size, Mean, Variance for t…
  2. 102.If the mean and variance of the following data: 6, 10, 7, 13, a, 12, b, 12 are 9 and 374 r…
  3. 103.Let the mean and variance of the frequency distribution be 6 and 6.8, respectively.
  4. 104.Consider the following frequency distribution.
  5. 105.The first of the two samples in a group has 100 items with mean 15 and standard deviation …
  6. 106.Consider the following frequency distribution.
  7. 107.The mean of 6 distinct observations is 6.5 and their variance is 10.25.
  8. 108.If the mean and variance of six observations 7, 10, 11, 15, a, b are 10 and 203, respectiv…
  9. 109.The mean of 10 numbers 78, 1010, 1312, 1614, is Answer: 398
  10. 110.The mean and variance of 7 observations are 8 and 16 respectively.
  11. 111.Let n be an odd natural number such that the variance of 1,2,3,4,,n is 14.
  12. 112.An online exam is attempted by 50 candidates out of which 20 are boys.
  13. 113.The mean and standard deviation of 20 observations were calculated as 10 and 2.5 respectiv…
  14. 114.Let the mean and variance of four numbers 3, 7, x and y (x>y) be 5 and 10 respectively.
  15. 115.If the mean of X is 2.3 and variance of X is ^2, then 100^2 is equal to Answer: 781
  16. 116.Let the observations x_i (1 i10) satisfy the equations _i=1^10(x_i-5)=10 and _i=1^10(x_i-5…
  17. 117.The mean and the standard deviation (s.d.) of 10 observations are 20 and 2 respectively.
  18. 118.The mean and variance of 20 observations are found to be 10 and 4, respectively.
  19. 119.If the variance of the first n natural numbers is 10 and the variance of the first m even …
  20. 120.If the mean and variance of eight numbers 3, 7, 9, 12, 13, 20, x and y be 10 and 25 respec…
  21. 121.Consider the data on x taking the values 0,2,4,8,,2^n with frequencies n0,n1,n2,,nn respec…
  22. 122.*(This item, "The minimum value of 2^ x+2^ x", is a trigonometry/AM-GM question, not a Sta…
  23. 123.If _i=1^n(x_i-a)=n and _i=1^n(x_i-a)^2=na, (n,a>1), then the standard deviation of n obser…
  24. 124.The mean and variance of 7 observations are 8 and 16, respectively.
  25. 125.If the mean and the standard deviation of the data 3, 5, 7, a, b are 5 and 2 respectively,…
  26. 126.The mean and variance of 8 observations are 10 and 13.5, respectively.
  27. 127.If a variance of the following frequency distribution is 50, then x is equal to _____.
  28. 128.where 0<x_1<x_2<x_3<<x_15=10 and _i=1^15f_i>0, the standard deviation cannot be:
  29. 129.Let x_i (1 i10) be ten observations of a random variable X.
  30. 130.Let X = xN: 1 x17 and Y=ax+b: x X and a,bR, a>0.
  31. 131.If the variance of the terms in an increasing A.P.
  32. 132.If the sum of the deviations of 50 observations from 30 is 50, then the mean of these obse…
  33. 133.The mean and the variance of five observations are 4 and 5.20, respectively.
  34. 134.The outcome of each of 30 items was observed; 10 items gave an outcome 12-d each, 10 items…
  35. 135.A data consists of n observations: x_1,x_2,,x_n.
  36. 136.The mean of five observations is 5 and their variance is 9.20.
  37. 137.If mean and standard deviation of 5 observations x_1,x_2,x_3,x_4,x_5 are 10 and 3, respect…
  38. 138.5 students of a class have an average height 150 cm and variance 18 cm^2.
  39. 139.If for some xR, the frequency distribution of the marks obtained by 20 students in a test …
  40. 140.The mean and the median of the following ten numbers in increasing order 10, 22, 26, 29, 3…
  41. 141.If the data x_1,x_2,,x_10 is such that the mean of first four of these is 11, the mean of …
  42. 142.If both the mean and the standard deviation of 50 observations x_1,x_2,,x_50 are equal to …
  43. 143.If the standard deviation of the numbers -1,0,1,k is √5 where k>0, then k is equal to:
  44. 144.The mean and variance of seven observations are 8 and 16, respectively.
  45. 145.The mean of a set of 30 observations is 75.
  46. 146.The mean and the standard deviation (s.d.) of five observations are 9 and 0, respectively.
  47. 147.If the mean of the data: 7, 8, 9, 7, 8, 7, , 8 is 8, then the variance of this data is
  48. 148.If _i=1^9(x_i-5)=9 and _i=1^9(x_i-5)^2=45, then the standard deviation of the 9 items x_1,…
  49. 149.The mean age of 25 teachers in a school is 40 years.
  50. 150.The sum of 100 observations and the sum of their squares are 400 and 2475, respectively.