Question

Statistics question (please show thorough working):

- Part a):

Public health authorities want to estimate the proportion of Australians aged 18-65 who caught the flu during winter 2018. If the true proportion is thought to be about 24%, how large a sample will be needed if we want to be 95% sure that our estimate will be within 0.02 of the true value?

- Part b):

Due to a change in the available funding, the sample actually used for estimating the prevalence of flu included 1,712 randomly-selected Australians aged 18-65. Of these, 367 reported having a “flu-like illness” during winter 2018. Use these data to calculate a 90% confidence interval for the proportion of Australians aged 18-65 who had a flu-like illness during winter 2018.

Answer 1