:11. Solution. Adding the same number to each member of a list does not change its SD. Adding 1 to each member of -1,-1,-1,-1,1, we see that 0,0,0,0,2 has the same SD. But 0,0,0,0,2 is obtained from 0,0,0,0,1 by multiplying each member by 2. Multiplying each member of a list by a positive number multiplies the SD by the same number. Since the SD of 0,0,0,0,1 is .4, the SD of 0,0,0,0,2 is .8