The life in hours of a battery is known to be approximately normally distributed with standard deviation σ = 1.25 hours. a random sample of 10 batteries has a mean life of x =40.5hours. a. is there evidence to support the claim that battery life exceeds 40 hours? use α = 0.05. b. what is the p-value for the test in part (a)? c. what is the β-error for the test in part (a) if the true mean life is 42 hours? d. what sample size would be required to ensure that β does not exceed 0.10 if the true mean life is 44 hours? e. explain how you could answer the question in part (a) by calculating an appropriate confidence bound on life.

introduction, methodology, results, discussion

step-by-step explanation:

an observational study is one which consists of actual observation to record data and then analyse the data.

there are a number of factors that should be analyzed before starting an observational study.

the main four factors are:

i) introduction:   this should be analysed to check whether the purpose of the study is correctly established and the data recorded are appropriate for the study

methodology:   the method of collecting the data, such as whether randomly selected, and whether sample size matches with the population to be studied, whether questions asked are easy to answer by common men, etc.

results: then results such as summary of data with comments should be studied thoroughly

discussion:   the last is the discussion, this can be either by management people or persons who are all interested , etc.

the discriminant is 64 + 4*1*12 = 112

this is prime.

step-by-step explanation: