Assistance for study hypothesis and stat analysis

I require assistance for a study hypothesis and statistical analysis plan for the below.

(1) Research question : To find time to stop bleeding with use of product.

(2) Data Collection : Time take to stop bleeding will be captured with use of a stop watch. Eg. Patient 1= 5 minutes; Patient 2 = 4 minutes.

Sample size: As per attached reference from literature: Considering that similar product with take 5.6 minutes to stop bleeding and standard population takes 8.4±3.5 minutes, minimum number of patients required for study = 12 (sample size calculation attached). Please confirm if this is the correct way to calculate sample size.

Please help to know how can I perform stat analysis and what study hypothesis should I consider.

Kindly revert back for further information.