Flow meters are installed in urban sewer systems to measure the flows through the pipes. In dry weather conditions (no rain) the flows are generated by waste water from households and industries, together with some possible drainage from water stored in the topsoil from previous rainfalls. In a study of an urban sewer system, the values given in DS 8.5.1 were obtained for flow rates during dry weather conditions.
(a) What is the sample mean?
(b) What is the sample median?
(c) What is the sample standard deviation?
(d) Construct a 99% two-sided confidence interval for the average fairwater under dry weather conditions.
(e) Construct a 95% one-sided confidence interval that provides an upper bound for the average fairwater under dry weather conditions.
(f) If a 99% two-sided confidence interval for the average fairwater under dry weather conditions is required with a length no larger than 50. how much additional sampling would you recommend?
(g) Show how to test H0 : μ = 440 against HA : μ = 440.
(h) Show how to test H0: μ > 480 against HA: n < 480.