A sample of size 19 selected from a population produced a mean of 1.6. Another sample of
size 20 selected from another population produced a mean of 4.67. Assume that the two
populations are normally distributed with standard deviations 1.3 and 1.1, respectively.
The ninety percent confidence interval for the difference between the two population
means is:
a. (-3.722, -2.418)
b. [-3.965, -2.175)
c. [-3.648, -2.492)
d. [-3.886, -2.254)
e. [-3.706, -2.434]