In: Statistics and Probability
1. On the basis of her experience with clients, a clinical psychologist thinks that depression may decrease sleep. She decides to test this idea. The sleep of eight depressed patients and eight normal controls is monitored for three successive nights. The average number of hours slept by each subject during the last two nights is shown in the following table
Depressed patients: 7.1, 6.8, 6.7, 7.3, 7.5, 6.2,6.9, 6.5
Normal controls: 8.2, 7.5, 7.7, 7.8, 8.0, 7.4, 7.3, 6.5
A. what test would be appropriate?
B. Show your results.
C. What can you conclude using an alpha=0.05 based on these results? Report your result properly (t(df)= t obt, p <> alpha) and state the MEANING of your conclusion.
We use T-test for two population means
First of all we calculate mean and standard deviation for both samples.
For Depressed patients :
For Normal controls :
Now,
Hence, there is enough evidence to conclude that depression decreases sleep at 5% level of significance.