Q58.The mean and variance of 20 observations are found to be 10 and 4, respectively. On rechecking, it was found that an observation 9 was incorrect and the correct observation was 11, then the correct variance is (1) 3.99 (2) 4.01 (3) 4.02 (4) 3.98
What This Question Tests
This question tests the understanding of how to correct the mean and variance of a dataset when an incorrect observation is replaced by a correct one.
Concepts Tested
Formulas Used
Mean = Σx/n
Variance = (Σx^2/n) - (Mean)^2
📚 NCERT Sections This Tests
4.13 — How Is The Variability In Oxidation States Of Transition Metals Different From
Chemistry Class 11 · Chapter 4
4.13 How is the variability in oxidation states of transition metals different from that of the non transition metals? Illustrate with examples.
1.18 — A Point Charge Of 2.0 Mc Is At The Centre Of A Cubic Gaussian
Physics Class 11 · Chapter 1
1.18 A point charge of 2.0 mC is at the centre of a cubic Gaussian surface 9.0 cm on edge. What is the net electric flux through the surface?
13.2 — Obtain The Binding Energy Of The Nuclei 5626Fe And 20983 Bi In Units Of
Physics Class 12 · Chapter 13
13.2 Obtain the binding energy of the nuclei 5626Fe and 20983 Bi in units of MeV from the following data: m ( 5626Fe ) = 55.934939 u m ( 20983 Bi ) = 208.980388 u
📋 Question Details
- Chapter
- Statistics
- Topic
- Mean and Variance of Data
- Year
- 2020
- Shift
- 08 Jan Shift 2
- Q Number
- Q58
- Type
- MCQ
- NCERT Ref
- Class 11 Mathematics Ch 15: Statistics
More from this Chapter
Q98.The average marks of boys in a class is 52 and that of girls is 42 . The average marks of boys and girls combined is 50 . The percentage of boys in the class is (1) 40 (2) 20 (3) 80 (4) 60
Q84.The mean of the numbers a, b, 8, 5, 10 is 6 and the variance is 6.80. Then which one of the following gives possible values of a and b ? (1) a = 0, b = 7 (2) a = 5, b = 2 (3) a = 1, b = 6 (4) a = 3, b = 4 JEE Main 2008 JEE Main Previous Year Paper
Q71.If the mean deviation of number 1, 1 + d, 1 + 2d, … . , 1 + 100d from their mean is 255 , then the d is equal to (1) 10.0 (2) 20.0 (3) 10.1 (4) 20.2
Q72.Statement-1 : The variance of first n even natural numbers is n2−14 Statement-2 : The sum of first n natural numbers is n(n+1) 2 and the sum of squares of first n natural numbers is n(n+1)(2n+1)6 (1) Statement-1 is true, Statement-2 is true; (2) Statement-1 is true, Statement-2 is true; Statement-2 is a correct explanation for Statement-2 is not a correct explanation for Statement-1 Statement-1 (3) Statement-1 is true, Statement-2 is false (4) Statement-1 is false, Statement-2 is true