D Question 20 4 pts Consider taking random samples of size 50 from Population A with mean 15 and standard deviation 3 and random samples of size 75 from Population B with mean 10 and standard deviation 5. Use the provided formula sheet to calculate the standard error of the distribution of differences in sample means, CA CB. Standard error = [Select ] How many degrees of freedom should be used when conducting inference for HA - HB with samples of this size? Degrees of freedom = [ Select ]