Question

1. A researcher gathers four sets of identical twins so that she can explore the effect of a new energy drink on alertness levels. For each pair of twins, she gives one twin a placebo and the other the energy pill; one hour later, she has them complete a reaction time test. The energy pill is expected to produce different reaction times; does it?

Placebo	Energy Pill
10	8
12	10
12	8
15	10

Perform an appropriate two-tailed test of the significance of the mean difference.

Hypotheses:                     

t _obs=                         

t_crit=                              

df =                       

Mean difference =  

Experimental conclusion (Write out):

Find the 95% CI for this data:

2. A researcher is interested in the effect of exercise on mood. She had participants take a mood measure prior to completing a one hour cardio class and then again one hour after the class had ended. Did exercising change mood, as she expected?

Pre-exercise	Post-exercise
5	10
6	8
2	5
7	7
9	10

Perform an appropriate two-tailed test of the significance of the mean difference.

Hypotheses:                     

t _obs=                         

t_crit=                               

df =                       

Mean difference =  

Experimental conclusion (Write out):

Find the 95% CI for this data:

Answer 1