25 plz Share with your friends Share 0 Shipra Dang answered this Dear Student, Standard Deviation, S.D.=∑xi2n-∑xin2⇒3.5=4+9+a2+1214-2+3+a+1142⇒3.52=134+a24-16+a42⇒494=134+a24-256+a2+32a16⇒49=536+4a2-256-a2-32a4⇒196=280+3a2-32a⇒3a2-32a+84=0 Regards, 0 View Full Answer