I have a question can someone tell me what the check s1^2/s2^2 mean?

I have a question can someone tell me what the check s1^2/s2^2 mean? S= standard deviation. The BOLD lettering and numbers.

The main trial is conducted and involves a total of 200 patients.  Patients are enrolled and randomized to receive either the experimental medication or the placebo.  The data shown below are data collected at the end of the study after 6 weeks on the assigned treatment.

Experimental (n=100)

Placebo (n=100)

Mean (Std Dev) Systolic Blood Pressure

120.2 (15.4)

131.4 (18.9)

% Hypertensive

14%

22%

% With Side Effects

6%

8%

1. Generate a 95% confidence interval for the difference in mean systolic blood pressures between groups.