Can you please answer the (iv) & (v) sub parts. In a random sample of 100 batteries produced by a certain method, the average lifetime was 150 hours and the standard deviation was 25 hours. (i) Find a 95% confidence interval for the mean lifetime of batteries produced by this model. (ii) Find a 99% confidence interval for the mean lifetime of batteries produced by this model. (iii) An engineer claims that the mean lifetime is between 147 and 153 hours. With what level of confidence can this statement is made? (iv) Approximately how many batteries must be sampled so that a 95% confidence interval will specify the mean to within ±2 hours? (v) Approximately how many batteries must be sampled so that a 99% confidence interval will specify the mean to within ±2 hours?
Thank you very much for answering me. Can you please answer the (iv) & (v) sub parts.
In a random sample of 100 batteries produced by a certain method, the average
lifetime was 150 hours and the standard deviation was 25 hours.
(i) Find a 95% confidence interval for the
model.
(ii) Find a 99% confidence interval for the mean lifetime of batteries produced by this
model.
(iii) An engineer claims that the mean lifetime is between 147 and 153 hours. With what
level of confidence can this statement is made?
(iv) Approximately how many batteries must be sampled so that a 95% confidence
interval will specify the mean to within ±2 hours?
(v) Approximately how many batteries must be sampled so that a 99% confidence
interval will specify the mean to within ±2 hours?
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