Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
AP EAMCET202022 Sep 2020Morning ShiftMathematicsStatisticsActual

Calculate variance if x_i^2=18000 and x_i=960 , for 60 observations

Options

  1. A44
  2. B22
  3. C32
  4. D6.63

Correct answer

A. 44

Step-by-step solution

For 60 observations it's given that x_i=960 and x_i^2=18000 So, the variance = x_i^2 60 - ( x_i 60 )^2= 18000 60 - ( 960 60 )^2 =300-(16)^2=300-256=44

Practice Statistics on Quantrex Academy →

More from Statistics

The variance of a set of 20 observations is 16. If 7 is added to each observation, and then 5 is subtracted from each resulting observation, what will be the new standard deviation 2026If for a distribution of 20 items, (x - 4) = 10 and (x - 4)^2 = 85 then the standard deviation is: 2026Consider the data of scores obtained by students in an examination. If the score of every student is increased by 2 marks, then which of the following statements is TRUE? 2026The mean and standard deviation of 100 items are 50 and 4 , respectively then the sum of all squares of the items is 2026If _ i=1 ^9 (x_i-5 )=9 and _ i=1 ^9 (x_i-5 )^2=45 , then the standard deviation of the nine observations x ₁, x ₂, , x ₉ is 2025Variance of the following continuous frequency distribution is Class Interval 0 – 4 4 – 8 8 – 12 12 – 16 Frequency 1 2 2 1 2025The mean deviation from the median for the following data is x_i 9 3 7 2 5 f_i 1 6 2 8 4 2025The mean deviation about the mean for the following data is Class Interval 0 – 2 2 – 4 4 – 6 6 – 8 8 – 10 Frequency 1 3 4 1 2 2025 Full Statistics list All AP EAMCET PYQs