Table 10. Actural instrument flight evaluation
t
-test by age
Group
Obs
Mean
Std. Dev.
95% Conf. Interval
30y below
100
17.836
5.071
16.830 18.842
30y above
30
13.507
7.669
10.643 16.371
Diff
4.328
1.954 6.702
diff = mean(0) - mean(1)
t
= 3.607
Ho: diff = 0 degrees of freedom =128
Ha: diff < 0
Pr(T<
t
) = 0.9998
**
Ha: diff != 0
Pr(|T|>|
t
|) = 0.0004
Ha: diff > 0
Pr(T>
t
) = 0.0002
p
<.05