A clinical trial was conducted to test the effectiveness of a drug used for treating insomnia in older subjects. After treatment with the​ drug, 15 subjects had a mean wake time of 94.3 min and a standard deviation of 44.2 min. Assume that the 15 sample values appear to be from a normally distributed population and construct a ​90% confidence interval estimate of the standard deviation of the wake times for a population with the drug treatments. Does the result indicate whether the treatment is​ effective?

The correlation coefficient between the number of students and marks obtained in end semester exam. (13 marks) give the statistical meaning of the relationship between the number of students and marks b. obtained in end semester exam. (3 marks) draw the number of students and marks obtained in end semester exam scatter diagram c. (4 marks) check list write your name and id corectly write the question number properly use your own calculator. show all the steps to solve the problems. use the correct formula. answer in provided time. don't use your mobile for any purpose. write your answer up to two decimal places