Jee Main
Statistics
JEE Main 2021 (Online) 27th July Evening Shift
MCQ+4 / -12021
Let the mean and variance of the frequency distribution
\(\matrix{ {x:} & {{x_1} = 2} & {{x_2} = 6} & {{x_3} = 8} & {{x_4} = 9} \cr {f:} & 4 & 4 & \alpha & \beta \cr }\)
be 6 and 6.8 respectively. If x3 is changed from 8 to 7, then the mean for the new data will be :
\(\matrix{ {x:} & {{x_1} = 2} & {{x_2} = 6} & {{x_3} = 8} & {{x_4} = 9} \cr {f:} & 4 & 4 & \alpha & \beta \cr }\)
be 6 and 6.8 respectively. If x3 is changed from 8 to 7, then the mean for the new data will be :