Ztest A physiologist believes he has discovered a new steroi

Z-test: A physiologist believes he has discovered a new steroid hormone that can control the blood glucose in mammals. In an experiment he injects laboratory rats with a small amount of this putative steroid hormone and, after a suitable waiting period measures the blood glucose level of the rats. In his twelve experimental rats he obtains the following levels of blood glucose {35,36,37,33,34,35,33,35,37,36,34,35}. From previous studies of thousands of normal, un-manipulated rats he knows that the mean (?) blood glucose level in this species of rat (his laboratory population) is 31 and that the standard deviation (?) is 4.12. Use a Z-test to evaluate the directional hypothesis that this new steroid hormone decreases blood glucose levels. Use an alevel of 0.05 for this analysis. A) what is the null hypothesis? B) what is the alternative hypothesis? C) what is the critical value with and alpha of .05? D) what is Z obt? E) what should the cognitive psychologist conclude?

Solution

H0: