The distance travelled by a scooter during five months are respectively 890 km, 940 km, 640 km, 570 km and 760 km. Find the standard deviation of the distances.
141.3 km
Mean=890+940+640+570+7605=760 km
σ=√∑(X−¯X)2N=√15×[1302+1802+1202+1902+0]√998005=√19960=141.3km