8. your mechanic estimates that the total weight of a filled tire for your particular vehicle is less than 20 pounds. suppose that the total tire weight for vehicles that have your particular sized tire is normally distributed with standard deviation () 1.25 pounds. a random sample of 55 tires (similar in size to yours) has a sample mean weight of 18.75 pounds. use the “4-step process as applied to tests of significance” to test your mechanic’s claim at the 0.01 level. i. state: what is the practical question that requires a statistical test? ii. plan: a) identify the parameter. b) list all given information from the data collected: c) state the null (h0) and alternative (ha) hypotheses. h0: ha: d) specify the level of significance, = e) determine the type of test. left-tailed right-tailed two-tailed f) sketch the region(s) of “extremely unlikely” test statistics. iii. solve: a) check the conditions for the test you plan to use. random sample? large enough population: sample ratio? large enough sample? b) calculate the test statistic c) determine (or estimate) the p-value. iv. conclude: a) make a decision about the about the null (reject h0 or fail to reject h0). b) interpret the decision in the context of the original claim.