Thank you for the opportunity to help you with your question!
the moon orbits the earth in a circle. If the "average distance" given
is between the center of the earth and the center of the moon, then the
radius of that circle is 3.84 x 10^8 m. Since circumference is 2πR,
that's 2π (3.84 x 10^8 m) = 2.41 x 10^9 m per orbit.
This orbit takes a total of 27.3 days. Since each day has 86,400
seconds, that's (27.3 days) (86,400 s/day) = 2,358,720 seconds.
So the average speed is distance / time, or (2.41 x 10^9 m) / (2358720 s) = 1020 m/s
Please appreciate my help and select my answer as the best! Thanks :)