A new post-surgical treatment is being compared with a standard treatment. Seven subjects receive the new treatment, while seven others (the controls) receive 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

Required:
Find a 98% confidence interval for the difference in the mean recovery times between treatment and control.

Step-by-step explanation:

For this case we have the following info given:

Treatment: 12 13 15 19 20 21 24

Control: 18 23 24 30 32 35 39

We can find the sample mean and deviations with the the following formulas:

And repaplacing we got:

the sample mean for treatment

the sample mean for treatment

the sample deviation for treatment

the sample deviation for control

the sample size for each sample

The degrees of freedom are given by:

The confidence interval for the difference of means is given by:

The confidence is 98% so then the significance is and . Then the critical value would be:

And replacing we got:

true

explanation: