Answer:
The standard deviation of a mean difference = 5.23
Step-by-step explanation:
Given:
Standard deviation of a sample taken from population A = 17.6
the number of samples = 25
Standard deviation of a sample taken from population B = 21.1
the number of samples = 30
To find:
the standard deviation of the mean difference
The standard deviation of a mean difference is given as:


The standard deviation of a mean difference = 5.23