16 Enough eggs One of the important issues for poultry farm
16. Enough eggs? - One of the important issues for poultry farmers is the production rate - the percentage of days on which a given hen actually lays an egg. Ideally, that would be 100% (an egg every day), but realistically, hens tend to lay eggs on about 3 of every 4 days. ISA Babcock wants to advertise the production rate for the B300 Later (see Exercise 14) as a 95% confidence interval with a margin of error of + or - 2%. How many hens must they collect data on?
Solution
Note that      
       
 n = z(alpha/2)^2 p (1 - p) / E^2      
       
 where      
       
 alpha/2 =    0.025  
 As there is no previous estimate for p, we set p = 0.5.      
       
 Using a table/technology,      
       
 z(alpha/2) =    1.959963985  
       
 Also,      
       
 E =    0.02  
 p =    0.5  
       
 Thus,      
       
 n =    2400.911763  
       
 Rounding up,      
       
 n =    2401   [ANSWER]

