In: Statistics and Probability
24 white-tailed lemours with high depression were divided
equally into two groups. Group 1 received treatment with depression
medicine. Second group was control group. At the end, levels of
serotnin were made. The results were as follows:
Treatment group (group 1): mean score 11.1mg/100ml and standard
deviation S1= 1.5
Control group (group 2): mean score 7.8mg/100ml, standard deviation
S2 = 2.0,
The populations are normally distributed with equal but unknown
variances.
Compute a 95% confidence interval of the difference µ1- µ2 (mean 1
- mean 2).
8. Solution :
Given that,
For group 1 : mean x1 = 11.1 , standard deviation s1 = 1.5 , n1 =
12
For group 2 : mean x2 = 7.8 , standard deviation s2 = 2.0 , n2 = 12
=> A 95% confidence interval of the difference between the
means µ1- µ2 is (1.8040,4.7960)