If the average cortisol level for this issue is 17 mcg/dl and the observed confidence interval range is 10 mcg/dl to 15 mcg/dl. In my opinion, it is evident that the mean cortisol level for this issue does not fall inside the confidence interval. Considering that the total average needs to fall under the confidence interval range, this model might not be suitable for the population. The sample was not within the range of having a good sample size since the average range has to remain within the average range. To try and have a higher possibility of averaging cortisol levels inside the confidence range, we can try to increase the sample size