{"id":6962,"date":"2021-10-22T02:18:38","date_gmt":"2021-10-21T20:48:38","guid":{"rendered":"https:\/\/mathemerize.com\/?p=6962"},"modified":"2021-10-25T09:32:38","modified_gmt":"2021-10-25T04:02:38","slug":"all-the-students-of-a-class-performed-poorly-in-mathematics-the-teacher-decided-to-give-grace-marks-of-10-to-each-of-the-students-which-statistical-measure-will-not-change-even-after-the-grace-marks","status":"publish","type":"post","link":"https:\/\/mathemerize.com\/all-the-students-of-a-class-performed-poorly-in-mathematics-the-teacher-decided-to-give-grace-marks-of-10-to-each-of-the-students-which-statistical-measure-will-not-change-even-after-the-grace-marks\/","title":{"rendered":"All the students of a class performed poorly in mathematics. The teacher decided to give grace marks of 10 to each of the students. Which statistical measure will not change even after the grace marks were given ?"},"content":{"rendered":"
All the students of a class performed poorly in mathematics. The teacher decided to give grace marks of 10 to each of the students. Which statistical measure will not change even after the grace marks were given ?<\/p>\n
(a) Mean<\/p>\n
(b) Median<\/p>\n
(c) Mode<\/p>\n
(d) Variance<\/p>\n
If initially all marks were given \\(x_i\\), then<\/p>\n
\\({\\sigma_i}^2\\) = \\(\\sum(x_i – \\bar{x})^2\\over N\\)<\/p>\n
Now, each is increased by 10.<\/p>\n
\\(\\therefore\\) \\({\\sigma_i}^2\\) = \\(\\sum((x_i + 10) – (\\bar{x} + 10))^2\\over N\\)<\/p>\n
= \\({\\sigma_i}^2\\)<\/p>\n
So, variance will not change whereas mean, median and mode will increase by 10.<\/p>\n
The mean and variance of a random variable X having a binomial distribution are 4 and 2 respectively, then P(X = 1) is<\/a><\/p>\n The median of a set of 9 distinct observations is 20.5. If each of the largest 4 observation of the set is increased by 2, then the median of the new is<\/a><\/p>\n The mean and the variance of a binomial distribution are 4 and 2, respectively. Then, the probability of 2 success is<\/a><\/p>\n In a series of 2n observations, half of them equals a and remaining half equal -a. If the standard deviation of the observation is 2, then |a| equal to<\/a><\/p>\n