Question

A researcher working for a drug company is interested in investigating the effect of storage  on the potency of one of the company’s drugs. 10 freshly produced bottles of the drug were  randomly selected and the potency measured. Another 10 freshly produced bottles of the  drug were randomly chosen and stored under controlled conditions for six months before  the potency was measured. Summary statistics are displayed below:
Storage  n  Mean Std. Deviation  Fresh 10 10.37 0.3234 Stored 10 9.83 0.2406 (a) Carry out a t‐test to investigate whether there is a difference between the underlying mean  potency of the freshly produced drug and the underlying mean potency of the drug when  stored for six months.     [ 10 marks ]  Notes:  (i) You must clearly show that you have followed the “Step‐by‐Step Guide to Performing a  Hypothesis Test by Hand” given in the Lecture Workbook, Page 12, Chapter 7.

  (ii)  At steps 5 and 8 it is necessary to use the t‐procedures tool on Canvas to determine  the standard error and the t‐multiplier. Look under: Assignments  Assignment 3

  (iii) At step 6 it is necessary to use either the t‐procedures tool on Canvas, a graphics  calculator, SPSS or Excel to determine the P‐value.

  (iv) Refer to the instructions on Page 1 of this assignment: “Hypothesis tests in this  assignment”.   

(b) Does the confidence interval given in part (a) contain the true value of the parameter?  Briefly explain.  

Answer 1