Suppose a comet has an orbital period of 309.1 years around the sun. what is it’s average distance from the sun?

As we know from kepler's law that

here we know that for earth we have time period T = 1 year and its average distance from Sun is 1 AU

so here from above equation we have

from above equation we have

as we also know that

so average distance will be

true is the correct answer

hope i