In the article “Dialyzable free cortisol after stimulation with synacthen” published in the journal Clinical Biochemistry (Vogeser et al., 2002), the authors reported the raw data given in Table 6.9 on the free cortisol in 10 patients at time 0 and 60 min following stimulation with synacthen. Use the data given in Table 6.9 to answer the following:

(a) Compute the differences in free cortisol after stimulation with synacthen for the 10 patients in the study.

(b) Compute an estimate of the mean difference in free cortisol after stimulation with synacthen.

(c) Compute the estimated standard error of the mean difference in free cortisol after stimulation with synacthen.

(d) Create a normal probability plot of the differences and assess the assumption of normality required for a small sample confidence interval for the mean.

(e) Compute a 95% confidence interval for the mean difference in free cortisol after stimulation with synacthen.