A researcher wants to estimate the 95% confidence interval for the mean length of stay for patients hospitalised with COVID-19. A sample of 36 patients' length of stay was taken and it was found that the mean length of stay was 10.4 days and the standard deviation in length of stay was 3.1 days. Assuming a normal distribution, calculate the 95% confidence interval without the help of STATA for the mean length of stay and show your working out. Interpret your answer.