A hint to get started
Distinguish a binomial tail from a CLT mean tail
In the stated probability model, a flu patient has a 98% chance of full recovery. Find the probability that (i) more than 2 in a sample of 20 do not recover fully marks; (ii) in fifty samples of 20 patients, the mean number not recovering fully is greater than 0.5. marks
[2009/NYJC/II/9(a)]
CJC · Review problems · Question 4
Use the non-recovery probability 0.02, and distinguish sample size 20 from the 50 repeated observations of its count.