(a) For a group containing 100 observations, the arithmetic mean and standard devia- tion are 8 and J10 5 For 50 observations selected from these 100 observations the mean and the stan- dard deviation...

Extracted text: (a) For a group containing 100 observations, the arithmetic mean and standard devia- tion are 8 and J10 5 For 50 observations selected from these 100 observations the mean and the stan- dard deviation are 10 and 2 respectively. Find the arithmetic means and the standard deviation of the other half.