Home
Class 12
MATHS
If for a sample of size 60, we have the ...

If for a sample of size 60, we have the following information `sumxi^2=18000a n dsumxi=960` , then the variance is
a)6.63
(b) 16
(c) 22
(d) 44

A

6.63

B

16

C

22

D

44

Text Solution

AI Generated Solution

The correct Answer is:
To find the variance of the given sample, we can use the formula for variance: \[ \sigma^2 = \frac{\sum x_i^2}{n} - \left(\frac{\sum x_i}{n}\right)^2 \] Where: - \(\sigma^2\) is the variance, - \(\sum x_i^2\) is the sum of the squares of the observations, - \(\sum x_i\) is the sum of the observations, - \(n\) is the sample size. Given: - \(n = 60\) - \(\sum x_i^2 = 18000\) - \(\sum x_i = 960\) ### Step 1: Calculate \(\frac{\sum x_i^2}{n}\) \[ \frac{\sum x_i^2}{n} = \frac{18000}{60} = 300 \] ### Step 2: Calculate \(\frac{\sum x_i}{n}\) \[ \frac{\sum x_i}{n} = \frac{960}{60} = 16 \] ### Step 3: Calculate \(\left(\frac{\sum x_i}{n}\right)^2\) \[ \left(\frac{\sum x_i}{n}\right)^2 = 16^2 = 256 \] ### Step 4: Substitute values into the variance formula \[ \sigma^2 = 300 - 256 \] ### Step 5: Calculate the variance \[ \sigma^2 = 44 \] Thus, the variance is \(44\). ### Conclusion The correct answer is (d) 44. ---

To find the variance of the given sample, we can use the formula for variance: \[ \sigma^2 = \frac{\sum x_i^2}{n} - \left(\frac{\sum x_i}{n}\right)^2 \] Where: - \(\sigma^2\) is the variance, ...
Promotional Banner

Topper's Solved these Questions

  • STATISTICS

    CENGAGE ENGLISH|Exercise Archives|10 Videos
  • STATISTICS

    CENGAGE ENGLISH|Exercise Exercise 11.2|6 Videos
  • SOLUTIONS AND PROPERTIES OF TRIANGLE

    CENGAGE ENGLISH|Exercise Comprehension Type|6 Videos
  • STRAIGHT LINE

    CENGAGE ENGLISH|Exercise Multiple Correct Answers Type|8 Videos

Similar Questions

Explore conceptually related problems

If for a sample of size 60, we have the following information sumx_i^2=18000 \ and \ sumx_i=960 , then the variance is (a) 6.63 (b) 16 (c) 22 (d) 44

If for a sample of size 60, we have the following information sum(x_(i))^2=18000 and sumx_(i)=960 , then the variance is

If for a sample of size 60, we have the following information sumx_i^2=18000 \ and \ sumx_i^2=960 , then the variance is (a) 6.63 (b) 16 (c) 22 (d) 44

The acid dissociation constant of uric acid is K_(a)=4.0xx10^(-6) M. The pH of a sample of urine is 6.0. What is the ratio of concentration of urate ion to uric acid in the urine? (a) 2.0 (b) 4.0 (c) 6.0 (d) 0.25

If .^(n)P_(3)+.^(n)C_(n-2)=14n , the value of n is (a) 5 (b) 6 (c) 8 (d) 10

y=x is tangent to the parabola y=ax^(2)+c . If c=2, then the point of contact is (a) (3,3) (b) (2,2) (c) (6,6) (d) (4,4)

Average height & variance of 5 students in a class is 150 and 18 respectively. A new student whose height is 156 cm is added to the group. Find new variance. (a) 20 (b) 22 (c) 16 (d) 14

Average height & variance of 5 students in a class is 150 and 18 respectively. A new student whose height is 156 cm is added to the group. Find new variance. (a) 20 (b) 22 (c) 16 (d) 14

Comprehension 1 Let a^((log)_b x)=c\ w h e r e\ a ,\ b ,\ c\ &\ x\ are parameters. On the basis of above information, answer the following questions: If a=2\ x=a^((log)_5 25)&\ c=sqrt(2) , then b is a. 2 b. \ 16 c. \ 12 d. 2

In Figure, if l_1 || l_2, the value of x is (a) 22 1/2 (b) 30 (c) 45 (d) 60

CENGAGE ENGLISH-STATISTICS-Exercises
  1. The range of the following set of observations 2,3,5,9, 8, 7, 6, 5, 7,...

    Text Solution

    |

  2. If each observation of a raw data whose variance is sigma is multiplie...

    Text Solution

    |

  3. The freezing point of nitrobenzene is 3^(@)C. When 1.2 g of chloroform...

    Text Solution

    |

  4. Variance of the data 2,4,6,8,10 is

    Text Solution

    |

  5. If the standard deviation of 0,1,2,3...9 is K, then the standard devia...

    Text Solution

    |

  6. For a given distribution of marks, the mean is 35.16 and its standard ...

    Text Solution

    |

  7. The mean and S.D of 1, 2, 3, 4, 5, 6 is

    Text Solution

    |

  8. The standard deviation of 25 numbers is 40. If each of the numbers in ...

    Text Solution

    |

  9. Consider any set of observations x(1),x(2),x(3),..,x(101). It is given...

    Text Solution

    |

  10. For (2n+1) observations x(1), x(2),-x(2),..,x(n),-x(n) and 0, where al...

    Text Solution

    |

  11. If barx is the mean of n observations x(1),x(2),x(3)……x(n), then the v...

    Text Solution

    |

  12. If the standard deviation of a variable xi ssigma , then standard devi...

    Text Solution

    |

  13. The standard deviation of data 6,5,9,13,12,8 and 10 is

    Text Solution

    |

  14. If the mean of 100 observations is 50 and their standard deviations is...

    Text Solution

    |

  15. The standard deviation of first 10 natural numbers is a) 8.25 (b) 6....

    Text Solution

    |

  16. Consider the numbers 1,2,3,4,5,6,7,8,9,10. If 1 is added to each num...

    Text Solution

    |

  17. Consider the first 10 positve integers .If we multiply each number by ...

    Text Solution

    |

  18. If for a sample of size 60, we have the following information sumxi^2=...

    Text Solution

    |

  19. The standard deviation of some temperature data in .^(@)C is 5 .If the...

    Text Solution

    |

  20. What is the standard deviation of the following data ? {:("Measureme...

    Text Solution

    |