is 0.80 against the alternative that it is not. (Simple Regression & Correlation] 06. (a) Duracell manufactures batteries that the CEO claims will last an average of 300 hours under normal use. A...

Extracted text: is 0.80 against the alternative that it is not. (Simple Regression & Correlation] 06. (a) Duracell manufactures batteries that the CEO claims will last an average of 300 hours under normal use. A researcher randomly selected 20 batteries from the production line and tested these batteries. The tested batteries had a mean life span of 270 hours with a standard deviation of 50 hours. Do wehave enough evidence to suggest that the claim of an average li fetime of 300 hours is false? b) Newborn babies are more likely to be boys than girls. A random sample found 13,173 boys were born among 25,468 newbom children. The sample proportion of boys was 0.5172. Is this sample evidence that the birth of boys is more common than the birth of girls in the entire population? Ilypothesis Testing