A health officer is trying to study the malaria situation of Africa. From the records of seasonal blood survey (SBS) results he came to understand that the proportion of people having malaria in Africa was 3.8% in 1978 BC. The size of the sample considered was 15000. He also realized that during the year that followed (1979BC), blood samples were taken from 10,000 randomly selected persons. The result of the 1979 BC seasonal blood survey showed that 200 persons were positive for malaria. Help the health officer in testing the hypothesis that the malaria situation of 1979 did not show any significant difference from that of 1978(take the level of significance, a= 0.1)

Abottled water distributor wants to estimate the amount of water contained in 1-gallon bottles purchased from a nationally known water bottling company. the water bottling company’s specifications state that the standard deviation of the amount of water is equal to 0.02 gallon. a random sample of 50 bottles is selected, and the sample mean amount of water per 1-gallon bottle is 0.995 gallon a. construct a 99% confidence interval estimate for the popula-tion mean amount of water included in a 1-gallon bottle. b. on the basis of these results, do you think that the distributor has a right to complain to the water bottling company? why? c. must you assume that the population amount of water per bottle is normally distributed here? explain. d. construct a 95% confidence interval estimate. how does this change your answer to (b)?