Need some help and explanation on 1aii and 1c.

Background There is a virus codenamed Covid-Pi spreading across the world. It is highly contagious and causes high mortality rates. A. Multi-Ministry Taskforce is set up to tackle the Cowd-Pi pandemic. Question 1 (a) In order to decide the quarantine period for people who are at risk having Covid-Pi virus, the Taskforce must know the incubation period of the virus, i.e., how long it causes a person to show symptom after he has contacted the virus. Worldwide Statistics shows that the incubation periods follow a Normal Distribution with a mean of 12 days and a standard deviation of 5 days. [i] Find the incubation period that only 3% of the Covid-Pi virus will last beyond before showing symptom in human bodies. {ii} The Taskforce takes a sample of 15 airport arrival passengers who are tested positive for Covid-Pi vints. Evaluate the probability that the mean of their virus incubation periods will be more than [[1 days. Explain why this analysis can be conducted on a small sample size. [It] marks} Note: In Qfa't) d}: {a}, you shat! use relevant Statieesfannata and Standard Norma! Distribution tabte to derive the WES. (b) The fast vaccine that could ght the Covid-Pi virus was developed in February 2021 by Cosmos Pharmaceutical Limited {CPL}. It is named the Conqueror. A sample data was collected on its effective duration in weeks. i.e., how long the immunity lasts in a human body after the vaccination.