Question 5 A. A survey found that out of 150 citizens, 108 said they have received the first doze of Covid-19 injection. Find the 98% confidence interval of the population proportion of citizens who have received the first doze of Covid-19 injection. B. A bakery shop owner wishes to find the 90% confidence interval of the true mean cost of a large fruit cake. How large should the sample be if he wishes to be accurate to within $0.12? A previous study showed that the standard deviation of the price was $0.25. C. The average amount of time a person exercises daily is 22.7 minutes in a population. A random sample of 20 people showed an average of 29.8 minutes in time with a standard deviation of 9.8 minute. At =0.01, can it be concluded that the average differs from the population average? D. The average household income for a recent year in Fiji was $30,000. Five years earlier the average household income was $24,500. Assume sample sizes of 34 were used and the population standard deviations of both samples were $5928. At 5% level of significance is there enough evidence to believe that the average household income has increased?