Table 5.

Statistical data about differences between the two types of impressions.

Group	Obs	Mean	Std. Err.	Std. Dev	[95% Confidence.	Interval]
Group B	60	0.62295	0.0325056	0.2517873	0.5579064	0.6879936
Group C	60	0.9044833	0.0340743	0.263938	0.8363009	0.9726658
Combined	120	0.7637167	0.0267633	0.293177	0.7107227	0.8167106
Difference		−0.2815333	0.0470921		−0.3747886	−0.1882781

diff = mean(Group B)−mean(Group C); t = −5.9784. Ho: diff = 0 degrees of freedom = 118 Ha: diff < 0 Ha: diff = 0 Ha: diff > 0. Pr(T < t) = 0.0000 Pr(|T| > |t|) = 0.0000 Pr(T > t) = 1.0000; Std.Err—standard error; Std.Dev—standard deviation.