Herbie is the owner of a large chicken farm. He's curious about the proportion of underweight adult chickens on his farm, and would like to use a $95\%$ confidence interval to estimate the proportion of adult chickens that weigh less than $1.5$ $kg$. **What is the smallest number of chickens that Herbie must randomly sample in order to guarantee an interval with a margin of error of no more than $0.10$?** [[☃ radio 1]]