Answer: B. 1.679
Step-by-step explanation:
The standard deviation for the difference between two mean is given by :-
, where = sample size from population 1.
= sample size from population 2.
= sample mean differnce.
= sample standard deviations .
Given :
Then, the standard deviation of the difference between the two means will be :
The nearest option : B. 1.679
Hence, the standard deviation of the difference between the two means = 1.679