How do you say are you sure in spanish?

To one person ( informal ) ---------- ¿Estas seguro ?

To one person ( formal ) ----------------¿Esta seguro?

To more than one person ( mixed genders ) ¿ Estais seguros?

To more than one person ( all male ) ¿ Estais seguros?

To more than one person ( all female ) ¿ Estais seguras?