Consider the following results for independent random samples
taken from two populations.
Sample 1 
Sample 2 
n _{1} = 20 
n _{2} = 40 
x _{1} = 22.1 
x _{2} = 20.9 
s _{1} = 2.4 
s _{2} = 4.7

 What is the point estimate of the difference between the two
population means (to 1 decimal)?
 What is the degrees of freedom for the t distribution
(round down your answer to nearest whole number)?
 At 95% confidence, what is the margin of error (to 1
decimal)?
 What is the 95% confidence interval for the difference between
the two population means (to 1 decimal)? If your answer is negative
value, entre minus () sign. Use ztable.
( , )