Respuesta :
Answer:
The correct option is D.
Step-by-step explanation:
Confidence interval is used to express the degree of uncertainty associated with a sample statistic.
The confidence interval is calculated as,
[tex]\mu\pm z\cdot \frac{\sigma}{\sqrt{n}}[/tex]
The value of z score at 95% confidence interval is 1.96.
The confidence interval for given information is
[tex]245\pm 1.96\cdot \frac{\sigma}{\sqrt{n}}[/tex]
It is given that in each time of sampling the mean number of hours was outside the 95% confidence interval. It means σ can not be zero.
[tex]\sigma\neq 0[/tex]
[tex]\frac{\sigma}{\sqrt{n}}\neq 0[/tex]
It means the mean number of hours that the company's batteries last will be either below or above 245.
Therefore, the value can be anything, but not 245. The correct option is D.
