Can someone solve this problem?The first one is correct but (ii) is incorrect

(2 points) A particle has zero velocity initially (i.e., at time t = 0 ) and its acceleration at t seconds is a(t) = 32t - 4+3 meters-per-second per second. During the time interval [3, 6] seconds, (i) the average acceleration of this particle is -261 meters-per-second per second (ii) the average speed of this particle is 82867.32 meters-per-second