A product is produced by two different machines. Two random samples were selected, and the following
summary information were computed accordingly:
Machine 1 Machine 2
Sample size 80 100
Sample mean 4.5 gm 4.4 gm
Sample standard deviation 0.5 gm 0.6 gm
a) Estimate the 80% confidence interval of the difference between the two means.
b) What are the assumptions you considered for the above solution?