20 The probability of a person contracting a certain virus is 0.35. If it is assumed that a person contracting the virus is independent of others contracting it, in
a random sample of 12 persons, what is the standard deviation for the number of persons contracting the virus?
1 of 1
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Best answer that i found on yahoo ok   set :   x= length of 2nd piece in cm  x- 3= length of 1st piece in cm  x-4= length of 3rd piece in cm  then since you know they all came from the 20 cm ribbon you add them together and set them equal to 20x+ x-3 +x-4 = 20  3x - 7= 20  3x= 27  x= 9  the shortest piece is the third piece which is x- 4  x-4  9-4 = 5  the length of the smallest piece is 5 cm.  the other lengths are  9 cm  6 cm