米多人不怪 2017-8-2 07:24 PM
兩題數解唔通...求救5) A LCD display manufacturer has announced the release of a new IPS 32inch display panel. The production manager of the company claims that the average lifetime of the panel is longer than 15,000 hours. To support his claim, a random sample of 35 display panels of the same model is randomly selected from the production line and the corresponding average lifetime is 15,580 hours. From past experience, the distribution of the lifetime is known to be normally distributed with a standard deviation of 1,350 hours.
5i) At the 0.05 level of significance, is there any evidence to reveal that the average lifetime of the new panel is longer than 15,000 hours?
5ii) Use the p-value approach to test the hypothesis at the same level of significance.
5iii)With reference to the hypothesis test conducted by the production manager, what is the respective implication of a Type I error and a Type II error?
5iv)With reference to the result of the hypothesis test obtained in part (a) above, which kind of error (Type I or Type II) could not be possibly committed? Justify your answer.
7)The human resource manager of a large corporation has recently received complaints from quite a few employees, saying that there has been unfair treatment concerning workload between male staff and female staff. Those employees claim that more than 60% of all the employees in the corporation are of the same view. To verify the claim, 45 employees are randomly selected. Thirty of them expressed the view that there has been unfair treatment concerning workload between male staff and female staff.
7i) At the 0.01 level of significance, test whether the claim is justified or not.
7ii)Construct a 95% confidence interval estimate for the true proportion of employees who are of the view that there has been unfair treatment concerning workload. Keep your final answers to two decimal places.
7iii)Suppose that the managing director of the corporation is wondering whether selecting 45 employees as the sample is a correct choice or not and she would like to determine the actual sample size required. How large a random sample should be taken to estimate the concerned true corresponding proportion of employees to within ±0.1 with 98% confidence?
[[i] 本帖最後由 米多人不怪 於 2017-8-2 07:26 PM 編輯 [/i]]
大姑毒處 2017-8-4 08:08 PM
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5) A LCD display manufacturer has announced the release of a new IPS 32inch display panel. The production manager of the company claims that the average lifetime of the panel is longer than 15,000 hou ... [/quote]
[font=新細明體]唔係普通數學題嚟喎樓主, Statistics噃... :([/font]