Question and answer key (i) You must assume that the visibilities arenormally distributed.(ii) H,:µ = 14 nautical miles,H,:µ< 14 nautical miles1(iii) z= -2.284, significant(iv) Choosing 36 consecutive days to collect data isnot a good idea because weather patterns willensure that the data are not independent. Abetter sampling procedure would be to chooseevery tenth day. In this way the effects of weatherpatterns over the year would be eliminated. 6 The keepers of a lighthouse were required to keep records of weatherconditions. Analysis of their data from many years showed the visibility atmid-day to have a mean value of 14 nautical miles with standard deviation5.4 nautical miles. A new keeper decided he would test his theory that the airhad become less clear (and so visibility reduced) by carrying out a hypothesistest on data collected for his first 36 days on duty. His figures (in nauticalmiles) were as follows.35211271.51.510.250.2515171820161188.9.17353540.250.251128353516210.50.51(i) Write down a distributional assumption for the test to be valid.(ii) Write down suitable null and alternative hypotheses.(iii) Carry out the test at the 2.5% significance level and state the conclusionthat the lighthouse keeper would have come to.(iv) Criticise the sampling procedure used by the keeper and suggest a better one.

Name: Question and answer key (i) You must assume that the visibilities aren
Uploaded: 2024-03-20T06:38:44.000Z
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Description: Question and answer key (i) You must assume that the visibilities arenormally distributed.(ii) H,:µ = 14 nautical miles,H,:µ< 14 nautical miles1(iii) z= -2.284, significant(iv) Choosing 36 consecutive days to collect data isnot a good idea because we