In: Statistics and Probability
 Use the given statistics to complete parts (a) and (b). Assume that the populations are normally distributed. (a) Test whether μ1>μ2 at the alpha=0.01 level of significance for the given sample data. (b) Construct a 95% confidence interval about μ1−μ2.  | 
a) 
 = 1% = 0.01
Hypothesis:
Ho: 
1 = 
2
Ha: 
1 > 
2
First We need to find out, Degrees of Freedom
Degrees of Freedom:

Test statistic:

Critical value:
...............Using t table
Conclusion:
Test statistic < Critical value, 1.20 < 2.5835, That is Fail to Reject Ho at 1% level of significance.
b)
Critical value:
..............Using t table
95% Confidence Interval:


(-3.22, 11.62) OR -3.22 <  
1-
2
< 11.62
Here, Population mean difference = 0 i,e, 
1-
2=
0, Is included in this interval
That is, Fail to Reject Ho at 5% level of significance.