Homework  ch.  14 •  Does  consuming  caffeine  increase  perceived  a:ractiveness  of  others?  A  group  of  people  are  given  a  cup  of  coffee  and  asked  to  rate  random  pictures  from  1-­‐‑10  (mean  rating  =  7.5,  s  =  4,  n  =  36);  another  group  is  given  decaf  coffee  and  follows  the  same  procedure  (mean  =  6.0,  s  =  3,  n  =  36).

1.  State  the  null  hypothesis

2.  Calculate  t  observed  and  find  t  critical

3.  What  is  your  decision  and  interpretation/conclusion

4.  Find  a  99%  confidence  interval  for  the  difference  in  perceived  a:ractiveness  of  others  between  subjects  who  do  or  don’t  consume  caffeine