The mean of the answer is 20.5 because you add all of the number together and divide by 6 because there's 6 numbers.
I'm sorry, but I don't know how to do the standard deviation...
Hope this helped!
Alright
so
28% of 2 m³=0.28 times 2=0.56 m³ of silt in the first mixture
13% of the 1 m³=0.13 times 1=0.13 m³ of silt in 2nd
total is 0.56 m³+0.13 m³=0.69 m³ of silt
and the total is 2m³+1m³=3m³
so
0.69/3=0.23=23%
answer is D
List this from least to greatest:.5, 3/16, .75, 5.48
3/16 = 0.1875
so from least to greatest
3/16, .5, .75, 5.48