A weather map shows two cities along the same isobar. what does this indicate about the cities?

Keplers 3rd law tells us that the square of the orbital period of a planet is proportional to the cube of the semi-major axis if the planet.

p^2 = a^3

So if the orbital period is 29.46 years, then:

(29.46)^2 = a^3

867.8916 = a^3

9.54 au = a

So the average distance between Saturn and the Sun is 9.54 au

au = atronomical units. 

idk if i did this right, its been a while