Home
Class 11
MATHS
Let x(1), x(2),..., x(n) be n observati...

Let `x_(1), x_(2),..., x_(n)` be n observations. Let `w_(i)=l x_(i)+k` for i =1,2,..., n, where `l` and k are constants. If the mean of `x_(i)`'s is 48 and their standard deviation is 12, then the mean of `w_(i)`'s is 55 and their standard deviation is 15. The values of `l` and k should be

A

`l=1.25 , k=5`

B

`l= -1.25, k=5`

C

`l=2.5, k= -5`

D

`l=2.5, k=5`

Text Solution

Verified by Experts

The correct Answer is:
A
Promotional Banner

Similar Questions

Explore conceptually related problems

Let x _(1), x _(2), ... x _(n) be n observations such that sum x _(i) ^(2) = 400 and sum x _(i) = 80. Then a possible value of n is

The mean and variance of n observations x_(1), x_(2), x_(3),……..,x_(n) are 5 and 0 respectively. If sum_(i=1)^(n) x_(i)^(2) = 400 , then the value of n is equal to

Prove that the standard deviation from two values x_1 and x_2 of a variable x is equal to half their differences

If the roots of the quadratic equation m x^(2) - n x + k = 0 are tan 33^(@) and tan 12^(@) , then the value of (2m + n + k)/(m) is equal to

If the means of a set of observations x_(1), x_(2),…..x_(10) is 20, then the mean of x_(1)+4, x_(2)+8, x_(3)+12,….x_(10) +40 is

Consider the integral I=int(xe^x)/(1+x)^2dx What is the value of I