In: Statistics and Probability
2. A survey of a new postsurgical treatment was compared with a standard treatment. Seven subjects received the new treatment(cases), while seven others (Controls) received the standard treatment. The recovery times, in days, are given below. Treatment 12 13 15 19 20 21 24 Control 18 23 24 30 32 35 39 Can you conclude that the mean recovery time for those receiving the treatment is less than the mean for those receiving the standard treatment. Use a α=0.05 significance level.
a. Construct a 90% confidence interval for the difference in mean recovery time for those receiving the new treatment and others receiving the standard treatment.
b. Do the hypothesis test.
First we need to find the mean and SD of data sets. Following is the output of desciptive statistics generated by excel:
Box plots are almost symmetric for both data sets. There is no outlier to data sets. So we can assume that data sets are normally distributed. That is t test can be used.
(a)
(b)
Conclusion: There is evidence to conclude that the mean recovery time for those receiving the treatment is less than the mean for those receiving the standard treatment.