Question

1. In the population, the average IQ is 100 with a standard deviation of 15. A team of scientists wants to testa new medication to see if it has either a positive or negative effect on intelligence, or no effect at all. Asample of 30 participants who have taken the medication has a mean of 105. It is assumed that the data aredrawn from a normally distributed population. Did the medication affect intelligence, usingα= 0.05?

(a) State hypotheses appropriate to the research question.

(b) Describe what test would you use and state the reasons for your choice.

(c) Draw a conclusion in the context of the problem using the p-value.

(d) Construct a 95% CI forμ. Conclude in the context of the problem.

(e) Compute the power if the true population mean is 110. (please answer this one!!!)

Answer 1

To find out the power (power of test) we need the type of test and the test statistic used for the test. Beside this we need the level of significance for finding out the rejection region.

The poerp of test is the probability of rejecting the null under the true mean value.