The children on the basketball court do not stop playing while the artificial gravity aboard the starship is fluctuating. The height [math] of a thrown ball at time [math] is given by the table. The ball reaches its highest point at [math] seconds.

[math] in seconds00.20.40.60.81
[math] in feet00.21.52.11.70.9

Compute the average velocity of the ball from t=0.4 seconds to t=0.8 seconds.
average velocity = (include units)

Compute the average speed of the ball from t=0.4 seconds to t=0.8 seconds.
average speed = (include units)