4. In a factory there were 300 workers under flu infection, 75% of the workers were hospitalized. If half of the total workers survived after the treatment, find the confidence interval of the...

Solve these 3 questions.


Extracted text: 4. In a factory there were 300 workers under flu infection, 75% of the workers were hospitalized. If half of the total workers survived after the treatment, find the confidence interval of the proportion with a 3% significance level. Is the treatment effective? Why? 5. A manufacturer produces a new cooker and they claimed that it will reduce the fuel cost in half with 90% accuracy. Now design decision rule for the process with significance 0.05 by testing the cooker to 50 customers. 6. A company produces mosquito killing bat whose average lifetime is 360. days and average variation 60 days. It is claimed that in a newly developed process the mean lifetime can be increased. Design a decision rule for 100 samples with 0.1 significance. If the new process has increased the mean lifetime to 375 days, assuming a sample of 120 bulbs with estimated lifetime 370 days, find a and ß. Again, a sample of 80 cables is tested and it is found that the average lifetime is 368 days. Find the p-value of the test.