In a given data set mean of 40 observations is 50 and standard deviation is 12. Two readings which were 20 and 25, were mistakenly taken as 40 and 45. Find correct variance of data set
The mean of coefficients of x, x2, ....., x7 in the binomial expansion of (2 + x)9 is?
If [x+6]+[x+3] ≤ 7 and let call its solution as set A and set B is the solution of inequality 35x-8 < 3-3x.
Mean of first 15 numbers is 12 and variance is 14. Mean of next 15 numbers is 14 and variance is a. If variance of all 30 numbers is 13, then a is equal to