A sample of 35 observations has the means 80 and SD. As 4. A second sample of 65
Channel: Doubtnut
Date: 02/11/2021

A sample of 35 observations has the means 80 and SD. As 4. A second sample of 65 observations from the  same population has mean 70 and S.D.3. The S.D. of the combined sample is -