In testing the lethal concentration of a chemical found in polluted water. it is found that a certain concentration will kill 20% of the fish that are subjected to it for 24 hours. if 20 fish are placed in a tank containing this concentration of chemical. find the probability that after 24 hours : ) exactly 14 fish survive ? b) at least 10 survive ? c) at most 16 fish will die ?

a) 0.1091

b) 0.9994

c) 0.5886

Step-by-step explanation:

X = the number of fish out of 20 that die after 24 hours

x = 0, 1, 2, . . . , 20

X~ Binomial (n= 20, p =0.20)

P(14 survive) = P(X = 6)

= =0.1091

Similarly we can find out

P(at least 10 survive) = P( X <= 10 ) = (Using technology) = 0.9994

P(at most 16 will survive) = P(X <= 16) = (Using technology) = 0.5886

1/3 + 1/3 ≠ 2/6 because 1/3 alone = 2/6  

step by step explanation:

1/3 + 1/3 = 2/3       2/3=4/6