Answer:
a) Percent recovery
100%, 70.58%, 4.11%, 1.29% , 0% 
b) MBC = 160 ng mL
c) Static 
Explanation:
<u>A) Calculate the percent recovery for each group </u>
i) for 0ng mL 
( 3.4*10^5 / 3.4*10^5 ) * 100 = 100% 
ii) for 10ng mL 
( (2.4 * 10^5) / (3.4 * 10^5) ) * 100 = 70.58%
iii) for 20ng mL
( ( 6.4 * 10^5 ) / ( 3.4 * 10^5 ) ) * 100 = Nil
iv) for 40 ng mL 
( ( 1.4 * 10^4 ) / ( 3.4 * 10^5 ) ) * 100 = 4.11 %
v) for 80 ng mL 
( ( 4.4 * 10^3 ) / ( 3.4 * 10^5 ) ) * 100 = 1.29%
vi) for 160 n mL 
percentage recovery = 0% 
<u>B) what is the MBC </u>
The value of MBC = 160 n mL because at this concentration CFU/mL = 0 
<u>c) determine if the antimicrobial tested is static or cidal </u>
condition : If, the ratio of MBC : MIC  is  ≤4 then novel compound is Cidal
MBC / MIC =  160ng / 10ng = 16 : 1 
hence we can conclude that the antimicrobial tested is STATIC