The standard deviation of 20 observations is√5 If each observation is multiplied by 2, find the standard deviation and variance of the resulting observations.
Mean and standard deviation of 100 observations were found to be 40 and 10 respectively. If at the time of calculation two observations were wrongly taken as 30 and 70 in place of 3 and 27 respectively, Find the correct standard deviation.
The mean and standard deviation of six observations are 8 and 4, respectively. If each observation is multiplied by 3, find the new mean and new standard deviation of the resulting observations.